diff options
Diffstat (limited to 'REORG.TODO/manual/examples')
43 files changed, 2783 insertions, 0 deletions
diff --git a/REORG.TODO/manual/examples/README b/REORG.TODO/manual/examples/README new file mode 100644 index 0000000000..7d0070fdd5 --- /dev/null +++ b/REORG.TODO/manual/examples/README @@ -0,0 +1,8 @@ +These are source files for example code that appears in The GNU C +Library Reference Manual. + +While the manual itself is licensed under the terms of the GNU Free +Documentation License, you can use these source files on their own +under the terms of the GNU General Public License as published by +the Free Software Foundation; version 2 of the License, or (at your +option) any later version. diff --git a/REORG.TODO/manual/examples/add.c b/REORG.TODO/manual/examples/add.c new file mode 100644 index 0000000000..9261f105da --- /dev/null +++ b/REORG.TODO/manual/examples/add.c @@ -0,0 +1,47 @@ +/* Example of a Variadic Function + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdarg.h> +#include <stdio.h> + +int +add_em_up (int count,...) +{ + va_list ap; + int i, sum; + + va_start (ap, count); /* Initialize the argument list. */ + + sum = 0; + for (i = 0; i < count; i++) + sum += va_arg (ap, int); /* Get the next argument value. */ + + va_end (ap); /* Clean up. */ + return sum; +} + +int +main (void) +{ + /* This call prints 16. */ + printf ("%d\n", add_em_up (3, 5, 5, 6)); + + /* This call prints 55. */ + printf ("%d\n", add_em_up (10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)); + + return 0; +} diff --git a/REORG.TODO/manual/examples/argp-ex1.c b/REORG.TODO/manual/examples/argp-ex1.c new file mode 100644 index 0000000000..9058595e9b --- /dev/null +++ b/REORG.TODO/manual/examples/argp-ex1.c @@ -0,0 +1,31 @@ +/* Argp example #1 -- a minimal program using argp + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +/* This is (probably) the smallest possible program that + uses argp. It won't do much except give an error + messages and exit when there are any arguments, and print + a (rather pointless) messages for --help. */ + +#include <stdlib.h> +#include <argp.h> + +int +main (int argc, char **argv) +{ + argp_parse (0, argc, argv, 0, 0, 0); + exit (0); +} diff --git a/REORG.TODO/manual/examples/argp-ex2.c b/REORG.TODO/manual/examples/argp-ex2.c new file mode 100644 index 0000000000..83bb85b107 --- /dev/null +++ b/REORG.TODO/manual/examples/argp-ex2.c @@ -0,0 +1,61 @@ +/* Argp example #2 -- a pretty minimal program using argp + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +/* This program doesn't use any options or arguments, but uses + argp to be compliant with the GNU standard command line + format. + + In addition to making sure no arguments are given, and + implementing a --help option, this example will have a + --version option, and will put the given documentation string + and bug address in the --help output, as per GNU standards. + + The variable ARGP contains the argument parser specification; + adding fields to this structure is the way most parameters are + passed to argp_parse (the first three fields are usually used, + but not in this small program). There are also two global + variables that argp knows about defined here, + ARGP_PROGRAM_VERSION and ARGP_PROGRAM_BUG_ADDRESS (they are + global variables because they will almost always be constant + for a given program, even if it uses different argument + parsers for various tasks). */ + +#include <stdlib.h> +#include <argp.h> + +const char *argp_program_version = + "argp-ex2 1.0"; +const char *argp_program_bug_address = + "<bug-gnu-utils@@gnu.org>"; + +/* Program documentation. */ +static char doc[] = + "Argp example #2 -- a pretty minimal program using argp"; + +/* Our argument parser. The @code{options}, @code{parser}, and + @code{args_doc} fields are zero because we have neither options or + arguments; @code{doc} and @code{argp_program_bug_address} will be + used in the output for @samp{--help}, and the @samp{--version} + option will print out @code{argp_program_version}. */ +static struct argp argp = { 0, 0, 0, doc }; + +int +main (int argc, char **argv) +{ + argp_parse (&argp, argc, argv, 0, 0, 0); + exit (0); +} diff --git a/REORG.TODO/manual/examples/argp-ex3.c b/REORG.TODO/manual/examples/argp-ex3.c new file mode 100644 index 0000000000..e37ab73408 --- /dev/null +++ b/REORG.TODO/manual/examples/argp-ex3.c @@ -0,0 +1,169 @@ +/* Argp example #3 -- a program with options and arguments using argp + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +/* This program uses the same features as example 2, and uses options and + arguments. + + We now use the first four fields in ARGP, so here's a description of them: + OPTIONS -- A pointer to a vector of struct argp_option (see below) + PARSER -- A function to parse a single option, called by argp + ARGS_DOC -- A string describing how the non-option arguments should look + DOC -- A descriptive string about this program; if it contains a + vertical tab character (\v), the part after it will be + printed *following* the options + + The function PARSER takes the following arguments: + KEY -- An integer specifying which option this is (taken + from the KEY field in each struct argp_option), or + a special key specifying something else; the only + special keys we use here are ARGP_KEY_ARG, meaning + a non-option argument, and ARGP_KEY_END, meaning + that all arguments have been parsed + ARG -- For an option KEY, the string value of its + argument, or NULL if it has none + STATE-- A pointer to a struct argp_state, containing + various useful information about the parsing state; used here + are the INPUT field, which reflects the INPUT argument to + argp_parse, and the ARG_NUM field, which is the number of the + current non-option argument being parsed + It should return either 0, meaning success, ARGP_ERR_UNKNOWN, meaning the + given KEY wasn't recognized, or an errno value indicating some other + error. + + Note that in this example, main uses a structure to communicate with the + parse_opt function, a pointer to which it passes in the INPUT argument to + argp_parse. Of course, it's also possible to use global variables + instead, but this is somewhat more flexible. + + The OPTIONS field contains a pointer to a vector of struct argp_option's; + that structure has the following fields (if you assign your option + structures using array initialization like this example, unspecified + fields will be defaulted to 0, and need not be specified): + NAME -- The name of this option's long option (may be zero) + KEY -- The KEY to pass to the PARSER function when parsing this option, + *and* the name of this option's short option, if it is a + printable ascii character + ARG -- The name of this option's argument, if any + FLAGS -- Flags describing this option; some of them are: + OPTION_ARG_OPTIONAL -- The argument to this option is optional + OPTION_ALIAS -- This option is an alias for the + previous option + OPTION_HIDDEN -- Don't show this option in --help output + DOC -- A documentation string for this option, shown in --help output + + An options vector should be terminated by an option with all fields zero. */ + +#include <stdlib.h> +#include <argp.h> + +const char *argp_program_version = + "argp-ex3 1.0"; +const char *argp_program_bug_address = + "<bug-gnu-utils@@gnu.org>"; + +/* Program documentation. */ +static char doc[] = + "Argp example #3 -- a program with options and arguments using argp"; + +/* A description of the arguments we accept. */ +static char args_doc[] = "ARG1 ARG2"; + +/* The options we understand. */ +static struct argp_option options[] = { + {"verbose", 'v', 0, 0, "Produce verbose output" }, + {"quiet", 'q', 0, 0, "Don't produce any output" }, + {"silent", 's', 0, OPTION_ALIAS }, + {"output", 'o', "FILE", 0, + "Output to FILE instead of standard output" }, + { 0 } +}; + +/* Used by @code{main} to communicate with @code{parse_opt}. */ +struct arguments +{ + char *args[2]; /* @var{arg1} & @var{arg2} */ + int silent, verbose; + char *output_file; +}; + +/* Parse a single option. */ +static error_t +parse_opt (int key, char *arg, struct argp_state *state) +{ + /* Get the @var{input} argument from @code{argp_parse}, which we + know is a pointer to our arguments structure. */ + struct arguments *arguments = state->input; + + switch (key) + { + case 'q': case 's': + arguments->silent = 1; + break; + case 'v': + arguments->verbose = 1; + break; + case 'o': + arguments->output_file = arg; + break; + + case ARGP_KEY_ARG: + if (state->arg_num >= 2) + /* Too many arguments. */ + argp_usage (state); + + arguments->args[state->arg_num] = arg; + + break; + + case ARGP_KEY_END: + if (state->arg_num < 2) + /* Not enough arguments. */ + argp_usage (state); + break; + + default: + return ARGP_ERR_UNKNOWN; + } + return 0; +} + +/* Our argp parser. */ +static struct argp argp = { options, parse_opt, args_doc, doc }; + +int +main (int argc, char **argv) +{ + struct arguments arguments; + + /* Default values. */ + arguments.silent = 0; + arguments.verbose = 0; + arguments.output_file = "-"; + + /* Parse our arguments; every option seen by @code{parse_opt} will + be reflected in @code{arguments}. */ + argp_parse (&argp, argc, argv, 0, 0, &arguments); + + printf ("ARG1 = %s\nARG2 = %s\nOUTPUT_FILE = %s\n" + "VERBOSE = %s\nSILENT = %s\n", + arguments.args[0], arguments.args[1], + arguments.output_file, + arguments.verbose ? "yes" : "no", + arguments.silent ? "yes" : "no"); + + exit (0); +} diff --git a/REORG.TODO/manual/examples/argp-ex4.c b/REORG.TODO/manual/examples/argp-ex4.c new file mode 100644 index 0000000000..37218af23e --- /dev/null +++ b/REORG.TODO/manual/examples/argp-ex4.c @@ -0,0 +1,183 @@ +/* Argp example #4 -- a program with somewhat more complicated options + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +/* This program uses the same features as example 3, but has more + options, and somewhat more structure in the -help output. It + also shows how you can `steal' the remainder of the input + arguments past a certain point, for programs that accept a + list of items. It also shows the special argp KEY value + ARGP_KEY_NO_ARGS, which is only given if no non-option + arguments were supplied to the program. + + For structuring the help output, two features are used, + *headers* which are entries in the options vector with the + first four fields being zero, and a two part documentation + string (in the variable DOC), which allows documentation both + before and after the options; the two parts of DOC are + separated by a vertical-tab character ('\v', or '\013'). By + convention, the documentation before the options is just a + short string saying what the program does, and that afterwards + is longer, describing the behavior in more detail. All + documentation strings are automatically filled for output, + although newlines may be included to force a line break at a + particular point. All documentation strings are also passed to + the `gettext' function, for possible translation into the + current locale. */ + +#include <stdlib.h> +#include <error.h> +#include <argp.h> + +const char *argp_program_version = + "argp-ex4 1.0"; +const char *argp_program_bug_address = + "<bug-gnu-utils@@prep.ai.mit.edu>"; + +/* Program documentation. */ +static char doc[] = + "Argp example #4 -- a program with somewhat more complicated\ +options\ +\vThis part of the documentation comes *after* the options;\ + note that the text is automatically filled, but it's possible\ + to force a line-break, e.g.\n<-- here."; + +/* A description of the arguments we accept. */ +static char args_doc[] = "ARG1 [STRING...]"; + +/* Keys for options without short-options. */ +#define OPT_ABORT 1 /* --abort */ + +/* The options we understand. */ +static struct argp_option options[] = { + {"verbose", 'v', 0, 0, "Produce verbose output" }, + {"quiet", 'q', 0, 0, "Don't produce any output" }, + {"silent", 's', 0, OPTION_ALIAS }, + {"output", 'o', "FILE", 0, + "Output to FILE instead of standard output" }, + + {0,0,0,0, "The following options should be grouped together:" }, + {"repeat", 'r', "COUNT", OPTION_ARG_OPTIONAL, + "Repeat the output COUNT (default 10) times"}, + {"abort", OPT_ABORT, 0, 0, "Abort before showing any output"}, + + { 0 } +}; + +/* Used by @code{main} to communicate with @code{parse_opt}. */ +struct arguments +{ + char *arg1; /* @var{arg1} */ + char **strings; /* [@var{string}@dots{}] */ + int silent, verbose, abort; /* @samp{-s}, @samp{-v}, @samp{--abort} */ + char *output_file; /* @var{file} arg to @samp{--output} */ + int repeat_count; /* @var{count} arg to @samp{--repeat} */ +}; + +/* Parse a single option. */ +static error_t +parse_opt (int key, char *arg, struct argp_state *state) +{ + /* Get the @code{input} argument from @code{argp_parse}, which we + know is a pointer to our arguments structure. */ + struct arguments *arguments = state->input; + + switch (key) + { + case 'q': case 's': + arguments->silent = 1; + break; + case 'v': + arguments->verbose = 1; + break; + case 'o': + arguments->output_file = arg; + break; + case 'r': + arguments->repeat_count = arg ? atoi (arg) : 10; + break; + case OPT_ABORT: + arguments->abort = 1; + break; + + case ARGP_KEY_NO_ARGS: + argp_usage (state); + + case ARGP_KEY_ARG: + /* Here we know that @code{state->arg_num == 0}, since we + force argument parsing to end before any more arguments can + get here. */ + arguments->arg1 = arg; + + /* Now we consume all the rest of the arguments. + @code{state->next} is the index in @code{state->argv} of the + next argument to be parsed, which is the first @var{string} + we're interested in, so we can just use + @code{&state->argv[state->next]} as the value for + arguments->strings. + + @emph{In addition}, by setting @code{state->next} to the end + of the arguments, we can force argp to stop parsing here and + return. */ + arguments->strings = &state->argv[state->next]; + state->next = state->argc; + + break; + + default: + return ARGP_ERR_UNKNOWN; + } + return 0; +} + +/* Our argp parser. */ +static struct argp argp = { options, parse_opt, args_doc, doc }; + +int +main (int argc, char **argv) +{ + int i, j; + struct arguments arguments; + + /* Default values. */ + arguments.silent = 0; + arguments.verbose = 0; + arguments.output_file = "-"; + arguments.repeat_count = 1; + arguments.abort = 0; + + /* Parse our arguments; every option seen by @code{parse_opt} will be + reflected in @code{arguments}. */ + argp_parse (&argp, argc, argv, 0, 0, &arguments); + + if (arguments.abort) + error (10, 0, "ABORTED"); + + for (i = 0; i < arguments.repeat_count; i++) + { + printf ("ARG1 = %s\n", arguments.arg1); + printf ("STRINGS = "); + for (j = 0; arguments.strings[j]; j++) + printf (j == 0 ? "%s" : ", %s", arguments.strings[j]); + printf ("\n"); + printf ("OUTPUT_FILE = %s\nVERBOSE = %s\nSILENT = %s\n", + arguments.output_file, + arguments.verbose ? "yes" : "no", + arguments.silent ? "yes" : "no"); + } + + exit (0); +} diff --git a/REORG.TODO/manual/examples/atexit.c b/REORG.TODO/manual/examples/atexit.c new file mode 100644 index 0000000000..fe14930ef8 --- /dev/null +++ b/REORG.TODO/manual/examples/atexit.c @@ -0,0 +1,32 @@ +/* Cleanups on Exit + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <stdlib.h> + +void +bye (void) +{ + puts ("Goodbye, cruel world...."); +} + +int +main (void) +{ + atexit (bye); + exit (EXIT_SUCCESS); +} diff --git a/REORG.TODO/manual/examples/db.c b/REORG.TODO/manual/examples/db.c new file mode 100644 index 0000000000..652662682d --- /dev/null +++ b/REORG.TODO/manual/examples/db.c @@ -0,0 +1,69 @@ +/* User and Group Database Example + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <grp.h> +#include <pwd.h> +#include <sys/types.h> +#include <unistd.h> +#include <stdlib.h> + +int +main (void) +{ + uid_t me; + struct passwd *my_passwd; + struct group *my_group; + char **members; + + /* Get information about the user ID. */ + me = getuid (); + my_passwd = getpwuid (me); + if (!my_passwd) + { + printf ("Couldn't find out about user %d.\n", (int) me); + exit (EXIT_FAILURE); + } + + /* Print the information. */ + printf ("I am %s.\n", my_passwd->pw_gecos); + printf ("My login name is %s.\n", my_passwd->pw_name); + printf ("My uid is %d.\n", (int) (my_passwd->pw_uid)); + printf ("My home directory is %s.\n", my_passwd->pw_dir); + printf ("My default shell is %s.\n", my_passwd->pw_shell); + + /* Get information about the default group ID. */ + my_group = getgrgid (my_passwd->pw_gid); + if (!my_group) + { + printf ("Couldn't find out about group %d.\n", + (int) my_passwd->pw_gid); + exit (EXIT_FAILURE); + } + + /* Print the information. */ + printf ("My default group is %s (%d).\n", + my_group->gr_name, (int) (my_passwd->pw_gid)); + printf ("The members of this group are:\n"); + members = my_group->gr_mem; + while (*members) + { + printf (" %s\n", *(members)); + members++; + } + + return EXIT_SUCCESS; +} diff --git a/REORG.TODO/manual/examples/dir.c b/REORG.TODO/manual/examples/dir.c new file mode 100644 index 0000000000..da6eef2a46 --- /dev/null +++ b/REORG.TODO/manual/examples/dir.c @@ -0,0 +1,41 @@ +/* Simple Program to List a Directory + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +/*@group*/ +#include <stdio.h> +#include <sys/types.h> +#include <dirent.h> +/*@end group*/ + +int +main (void) +{ + DIR *dp; + struct dirent *ep; + + dp = opendir ("./"); + if (dp != NULL) + { + while (ep = readdir (dp)) + puts (ep->d_name); + (void) closedir (dp); + } + else + perror ("Couldn't open the directory"); + + return 0; +} diff --git a/REORG.TODO/manual/examples/dir2.c b/REORG.TODO/manual/examples/dir2.c new file mode 100644 index 0000000000..a8390822b4 --- /dev/null +++ b/REORG.TODO/manual/examples/dir2.c @@ -0,0 +1,46 @@ +/* Simple Program to List a Directory, Mark II + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +/*@group*/ +#include <stdio.h> +#include <dirent.h> +/*@end group*/ + +static int +one (const struct dirent *unused) +{ + return 1; +} + +int +main (void) +{ + struct dirent **eps; + int n; + + n = scandir ("./", &eps, one, alphasort); + if (n >= 0) + { + int cnt; + for (cnt = 0; cnt < n; ++cnt) + puts (eps[cnt]->d_name); + } + else + perror ("Couldn't open the directory"); + + return 0; +} diff --git a/REORG.TODO/manual/examples/execinfo.c b/REORG.TODO/manual/examples/execinfo.c new file mode 100644 index 0000000000..c357fa48ed --- /dev/null +++ b/REORG.TODO/manual/examples/execinfo.c @@ -0,0 +1,54 @@ +/* Obtain a backtrace and print it. + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <execinfo.h> +#include <stdio.h> +#include <stdlib.h> + +/* Obtain a backtrace and print it to @code{stdout}. */ +void +print_trace (void) +{ + void *array[10]; + size_t size; + char **strings; + size_t i; + + size = backtrace (array, 10); + strings = backtrace_symbols (array, size); + + printf ("Obtained %zd stack frames.\n", size); + + for (i = 0; i < size; i++) + printf ("%s\n", strings[i]); + + free (strings); +} + +/* A dummy function to make the backtrace more interesting. */ +void +dummy_function (void) +{ + print_trace (); +} + +int +main (void) +{ + dummy_function (); + return 0; +} diff --git a/REORG.TODO/manual/examples/filecli.c b/REORG.TODO/manual/examples/filecli.c new file mode 100644 index 0000000000..50f4ef43ac --- /dev/null +++ b/REORG.TODO/manual/examples/filecli.c @@ -0,0 +1,71 @@ +/* Example of Reading Datagrams + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <errno.h> +#include <unistd.h> +#include <stdlib.h> +#include <sys/socket.h> +#include <sys/un.h> + +#define SERVER "/tmp/serversocket" +#define CLIENT "/tmp/mysocket" +#define MAXMSG 512 +#define MESSAGE "Yow!!! Are we having fun yet?!?" + +int +main (void) +{ + extern int make_named_socket (const char *name); + int sock; + char message[MAXMSG]; + struct sockaddr_un name; + size_t size; + int nbytes; + + /* Make the socket. */ + sock = make_named_socket (CLIENT); + + /* Initialize the server socket address. */ + name.sun_family = AF_LOCAL; + strcpy (name.sun_path, SERVER); + size = strlen (name.sun_path) + sizeof (name.sun_family); + + /* Send the datagram. */ + nbytes = sendto (sock, MESSAGE, strlen (MESSAGE) + 1, 0, + (struct sockaddr *) & name, size); + if (nbytes < 0) + { + perror ("sendto (client)"); + exit (EXIT_FAILURE); + } + + /* Wait for a reply. */ + nbytes = recvfrom (sock, message, MAXMSG, 0, NULL, 0); + if (nbytes < 0) + { + perror ("recfrom (client)"); + exit (EXIT_FAILURE); + } + + /* Print a diagnostic message. */ + fprintf (stderr, "Client: got message: %s\n", message); + + /* Clean up. */ + remove (CLIENT); + close (sock); +} diff --git a/REORG.TODO/manual/examples/filesrv.c b/REORG.TODO/manual/examples/filesrv.c new file mode 100644 index 0000000000..9cf3d0ee91 --- /dev/null +++ b/REORG.TODO/manual/examples/filesrv.c @@ -0,0 +1,65 @@ +/* Datagram Socket Example + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <errno.h> +#include <stdlib.h> +#include <sys/socket.h> +#include <sys/un.h> + +#define SERVER "/tmp/serversocket" +#define MAXMSG 512 + +int +main (void) +{ + int sock; + char message[MAXMSG]; + struct sockaddr_un name; + size_t size; + int nbytes; + + /* Remove the filename first, it's ok if the call fails */ + unlink (SERVER); + + /* Make the socket, then loop endlessly. */ + sock = make_named_socket (SERVER); + while (1) + { + /* Wait for a datagram. */ + size = sizeof (name); + nbytes = recvfrom (sock, message, MAXMSG, 0, + (struct sockaddr *) & name, &size); + if (nbytes < 0) + { + perror ("recfrom (server)"); + exit (EXIT_FAILURE); + } + + /* Give a diagnostic message. */ + fprintf (stderr, "Server: got message: %s\n", message); + + /* Bounce the message back to the sender. */ + nbytes = sendto (sock, message, nbytes, 0, + (struct sockaddr *) & name, size); + if (nbytes < 0) + { + perror ("sendto (server)"); + exit (EXIT_FAILURE); + } + } +} diff --git a/REORG.TODO/manual/examples/fmtmsgexpl.c b/REORG.TODO/manual/examples/fmtmsgexpl.c new file mode 100644 index 0000000000..5cd965cd3f --- /dev/null +++ b/REORG.TODO/manual/examples/fmtmsgexpl.c @@ -0,0 +1,29 @@ +/* How to use fmtmsg and addseverity. + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <fmtmsg.h> + +int +main (void) +{ + addseverity (5, "NOTE2"); + fmtmsg (MM_PRINT, "only1field", MM_INFO, "text2", "action2", "tag2"); + fmtmsg (MM_PRINT, "UX:cat", 5, "invalid syntax", "refer to manual", + "UX:cat:001"); + fmtmsg (MM_PRINT, "label:foo", 6, "text", "action", "tag"); + return 0; +} diff --git a/REORG.TODO/manual/examples/genpass.c b/REORG.TODO/manual/examples/genpass.c new file mode 100644 index 0000000000..7d76dedfbc --- /dev/null +++ b/REORG.TODO/manual/examples/genpass.c @@ -0,0 +1,49 @@ +/* Encrypting Passwords + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <time.h> +#include <unistd.h> +#include <crypt.h> + +int +main(void) +{ + unsigned long seed[2]; + char salt[] = "$1$........"; + const char *const seedchars = + "./0123456789ABCDEFGHIJKLMNOPQRST" + "UVWXYZabcdefghijklmnopqrstuvwxyz"; + char *password; + int i; + + /* Generate a (not very) random seed. + You should do it better than this... */ + seed[0] = time(NULL); + seed[1] = getpid() ^ (seed[0] >> 14 & 0x30000); + + /* Turn it into printable characters from `seedchars'. */ + for (i = 0; i < 8; i++) + salt[3+i] = seedchars[(seed[i/5] >> (i%5)*6) & 0x3f]; + + /* Read in the user's password and encrypt it. */ + password = crypt(getpass("Password:"), salt); + + /* Print the results. */ + puts(password); + return 0; +} diff --git a/REORG.TODO/manual/examples/inetcli.c b/REORG.TODO/manual/examples/inetcli.c new file mode 100644 index 0000000000..1723e2fc56 --- /dev/null +++ b/REORG.TODO/manual/examples/inetcli.c @@ -0,0 +1,76 @@ +/* Byte Stream Socket Example + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <errno.h> +#include <stdlib.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <netdb.h> + +#define PORT 5555 +#define MESSAGE "Yow!!! Are we having fun yet?!?" +#define SERVERHOST "www.gnu.org" + +void +write_to_server (int filedes) +{ + int nbytes; + + nbytes = write (filedes, MESSAGE, strlen (MESSAGE) + 1); + if (nbytes < 0) + { + perror ("write"); + exit (EXIT_FAILURE); + } +} + + +int +main (void) +{ + extern void init_sockaddr (struct sockaddr_in *name, + const char *hostname, + uint16_t port); + int sock; + struct sockaddr_in servername; + + /* Create the socket. */ + sock = socket (PF_INET, SOCK_STREAM, 0); + if (sock < 0) + { + perror ("socket (client)"); + exit (EXIT_FAILURE); + } + + /* Connect to the server. */ + init_sockaddr (&servername, SERVERHOST, PORT); + if (0 > connect (sock, + (struct sockaddr *) &servername, + sizeof (servername))) + { + perror ("connect (client)"); + exit (EXIT_FAILURE); + } + + /* Send data to the server. */ + write_to_server (sock); + close (sock); + exit (EXIT_SUCCESS); +} diff --git a/REORG.TODO/manual/examples/inetsrv.c b/REORG.TODO/manual/examples/inetsrv.c new file mode 100644 index 0000000000..01ae631818 --- /dev/null +++ b/REORG.TODO/manual/examples/inetsrv.c @@ -0,0 +1,120 @@ +/* Byte Stream Connection Server Example + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <errno.h> +#include <stdlib.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <netdb.h> + +#define PORT 5555 +#define MAXMSG 512 + +int +read_from_client (int filedes) +{ + char buffer[MAXMSG]; + int nbytes; + + nbytes = read (filedes, buffer, MAXMSG); + if (nbytes < 0) + { + /* Read error. */ + perror ("read"); + exit (EXIT_FAILURE); + } + else if (nbytes == 0) + /* End-of-file. */ + return -1; + else + { + /* Data read. */ + fprintf (stderr, "Server: got message: `%s'\n", buffer); + return 0; + } +} + +int +main (void) +{ + extern int make_socket (uint16_t port); + int sock; + fd_set active_fd_set, read_fd_set; + int i; + struct sockaddr_in clientname; + size_t size; + + /* Create the socket and set it up to accept connections. */ + sock = make_socket (PORT); + if (listen (sock, 1) < 0) + { + perror ("listen"); + exit (EXIT_FAILURE); + } + + /* Initialize the set of active sockets. */ + FD_ZERO (&active_fd_set); + FD_SET (sock, &active_fd_set); + + while (1) + { + /* Block until input arrives on one or more active sockets. */ + read_fd_set = active_fd_set; + if (select (FD_SETSIZE, &read_fd_set, NULL, NULL, NULL) < 0) + { + perror ("select"); + exit (EXIT_FAILURE); + } + + /* Service all the sockets with input pending. */ + for (i = 0; i < FD_SETSIZE; ++i) + if (FD_ISSET (i, &read_fd_set)) + { + if (i == sock) + { + /* Connection request on original socket. */ + int new; + size = sizeof (clientname); + new = accept (sock, + (struct sockaddr *) &clientname, + &size); + if (new < 0) + { + perror ("accept"); + exit (EXIT_FAILURE); + } + fprintf (stderr, + "Server: connect from host %s, port %hd.\n", + inet_ntoa (clientname.sin_addr), + ntohs (clientname.sin_port)); + FD_SET (new, &active_fd_set); + } + else + { + /* Data arriving on an already-connected socket. */ + if (read_from_client (i) < 0) + { + close (i); + FD_CLR (i, &active_fd_set); + } + } + } + } +} diff --git a/REORG.TODO/manual/examples/isockad.c b/REORG.TODO/manual/examples/isockad.c new file mode 100644 index 0000000000..be2def3be8 --- /dev/null +++ b/REORG.TODO/manual/examples/isockad.c @@ -0,0 +1,40 @@ +/* Internet Socket Example using sockaddr_in. + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <netdb.h> + +void +init_sockaddr (struct sockaddr_in *name, + const char *hostname, + uint16_t port) +{ + struct hostent *hostinfo; + + name->sin_family = AF_INET; + name->sin_port = htons (port); + hostinfo = gethostbyname (hostname); + if (hostinfo == NULL) + { + fprintf (stderr, "Unknown host %s.\n", hostname); + exit (EXIT_FAILURE); + } + name->sin_addr = *(struct in_addr *) hostinfo->h_addr; +} diff --git a/REORG.TODO/manual/examples/longopt.c b/REORG.TODO/manual/examples/longopt.c new file mode 100644 index 0000000000..40967174aa --- /dev/null +++ b/REORG.TODO/manual/examples/longopt.c @@ -0,0 +1,113 @@ +/* Example of Parsing Long Options with getopt_long. + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <getopt.h> + +/* Flag set by @samp{--verbose}. */ +static int verbose_flag; + +int +main (int argc, char **argv) +{ + int c; + + while (1) + { + static struct option long_options[] = + { + /* These options set a flag. */ + {"verbose", no_argument, &verbose_flag, 1}, + {"brief", no_argument, &verbose_flag, 0}, + /* These options don't set a flag. + We distinguish them by their indices. */ + {"add", no_argument, 0, 'a'}, + {"append", no_argument, 0, 'b'}, + {"delete", required_argument, 0, 'd'}, + {"create", required_argument, 0, 'c'}, + {"file", required_argument, 0, 'f'}, + {0, 0, 0, 0} + }; + /* @code{getopt_long} stores the option index here. */ + int option_index = 0; + + c = getopt_long (argc, argv, "abc:d:f:", + long_options, &option_index); + + /* Detect the end of the options. */ + if (c == -1) + break; + + switch (c) + { + case 0: + /* If this option set a flag, do nothing else now. */ + if (long_options[option_index].flag != 0) + break; + printf ("option %s", long_options[option_index].name); + if (optarg) + printf (" with arg %s", optarg); + printf ("\n"); + break; + + case 'a': + puts ("option -a\n"); + break; + + case 'b': + puts ("option -b\n"); + break; + + case 'c': + printf ("option -c with value `%s'\n", optarg); + break; + + case 'd': + printf ("option -d with value `%s'\n", optarg); + break; + + case 'f': + printf ("option -f with value `%s'\n", optarg); + break; + + case '?': + /* @code{getopt_long} already printed an error message. */ + break; + + default: + abort (); + } + } + + /* Instead of reporting @samp{--verbose} + and @samp{--brief} as they are encountered, + we report the final status resulting from them. */ + if (verbose_flag) + puts ("verbose flag is set"); + + /* Print any remaining command line arguments (not options). */ + if (optind < argc) + { + printf ("non-option ARGV-elements: "); + while (optind < argc) + printf ("%s ", argv[optind++]); + putchar ('\n'); + } + + exit (0); +} diff --git a/REORG.TODO/manual/examples/memopen.c b/REORG.TODO/manual/examples/memopen.c new file mode 100644 index 0000000000..407aeba878 --- /dev/null +++ b/REORG.TODO/manual/examples/memopen.c @@ -0,0 +1,34 @@ +/* String Streams + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> + +static char buffer[] = "foobar"; + +int +main (void) +{ + int ch; + FILE *stream; + + stream = fmemopen (buffer, strlen (buffer), "r"); + while ((ch = fgetc (stream)) != EOF) + printf ("Got %c\n", ch); + fclose (stream); + + return 0; +} diff --git a/REORG.TODO/manual/examples/memstrm.c b/REORG.TODO/manual/examples/memstrm.c new file mode 100644 index 0000000000..d339ffb95d --- /dev/null +++ b/REORG.TODO/manual/examples/memstrm.c @@ -0,0 +1,36 @@ +/* open_memstream example. + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> + +int +main (void) +{ + char *bp; + size_t size; + FILE *stream; + + stream = open_memstream (&bp, &size); + fprintf (stream, "hello"); + fflush (stream); + printf ("buf = `%s', size = %zu\n", bp, size); + fprintf (stream, ", world"); + fclose (stream); + printf ("buf = `%s', size = %zu\n", bp, size); + + return 0; +} diff --git a/REORG.TODO/manual/examples/mkdirent.c b/REORG.TODO/manual/examples/mkdirent.c new file mode 100644 index 0000000000..988e988460 --- /dev/null +++ b/REORG.TODO/manual/examples/mkdirent.c @@ -0,0 +1,42 @@ +/* Example for creating a struct dirent object for use with glob. + Copyright (C) 2016-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <dirent.h> +#include <errno.h> +#include <stddef.h> +#include <stdlib.h> +#include <string.h> + +struct dirent * +mkdirent (const char *name) +{ + size_t dirent_size = offsetof (struct dirent, d_name) + 1; + size_t name_length = strlen (name); + size_t total_size = dirent_size + name_length; + if (total_size < dirent_size) + { + errno = ENOMEM; + return NULL; + } + struct dirent *result = malloc (total_size); + if (result == NULL) + return NULL; + result->d_type = DT_UNKNOWN; + result->d_ino = 1; /* Do not skip this entry. */ + memcpy (result->d_name, name, name_length + 1); + return result; +} diff --git a/REORG.TODO/manual/examples/mkfsock.c b/REORG.TODO/manual/examples/mkfsock.c new file mode 100644 index 0000000000..ffe1b46928 --- /dev/null +++ b/REORG.TODO/manual/examples/mkfsock.c @@ -0,0 +1,62 @@ +/* Example of Local-Namespace Sockets + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stddef.h> +#include <stdio.h> +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <sys/un.h> + +int +make_named_socket (const char *filename) +{ + struct sockaddr_un name; + int sock; + size_t size; + + /* Create the socket. */ + sock = socket (PF_LOCAL, SOCK_DGRAM, 0); + if (sock < 0) + { + perror ("socket"); + exit (EXIT_FAILURE); + } + + /* Bind a name to the socket. */ + name.sun_family = AF_LOCAL; + strncpy (name.sun_path, filename, sizeof (name.sun_path)); + name.sun_path[sizeof (name.sun_path) - 1] = '\0'; + + /* The size of the address is + the offset of the start of the filename, + plus its length (not including the terminating null byte). + Alternatively you can just do: + size = SUN_LEN (&name); + */ + size = (offsetof (struct sockaddr_un, sun_path) + + strlen (name.sun_path)); + + if (bind (sock, (struct sockaddr *) &name, size) < 0) + { + perror ("bind"); + exit (EXIT_FAILURE); + } + + return sock; +} diff --git a/REORG.TODO/manual/examples/mkisock.c b/REORG.TODO/manual/examples/mkisock.c new file mode 100644 index 0000000000..5657322631 --- /dev/null +++ b/REORG.TODO/manual/examples/mkisock.c @@ -0,0 +1,48 @@ +/* Internet Socket Example + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <sys/socket.h> +#include <netinet/in.h> + +int +make_socket (uint16_t port) +{ + int sock; + struct sockaddr_in name; + + /* Create the socket. */ + sock = socket (PF_INET, SOCK_STREAM, 0); + if (sock < 0) + { + perror ("socket"); + exit (EXIT_FAILURE); + } + + /* Give the socket a name. */ + name.sin_family = AF_INET; + name.sin_port = htons (port); + name.sin_addr.s_addr = htonl (INADDR_ANY); + if (bind (sock, (struct sockaddr *) &name, sizeof (name)) < 0) + { + perror ("bind"); + exit (EXIT_FAILURE); + } + + return sock; +} diff --git a/REORG.TODO/manual/examples/mygetpass.c b/REORG.TODO/manual/examples/mygetpass.c new file mode 100644 index 0000000000..152d7bee7f --- /dev/null +++ b/REORG.TODO/manual/examples/mygetpass.c @@ -0,0 +1,42 @@ +/* Reading Passwords + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <termios.h> +#include <stdio.h> + +ssize_t +my_getpass (char **lineptr, size_t *n, FILE *stream) +{ + struct termios old, new; + int nread; + + /* Turn echoing off and fail if we can't. */ + if (tcgetattr (fileno (stream), &old) != 0) + return -1; + new = old; + new.c_lflag &= ~ECHO; + if (tcsetattr (fileno (stream), TCSAFLUSH, &new) != 0) + return -1; + + /* Read the password. */ + nread = getline (lineptr, n, stream); + + /* Restore terminal. */ + (void) tcsetattr (fileno (stream), TCSAFLUSH, &old); + + return nread; +} diff --git a/REORG.TODO/manual/examples/ofdlocks.c b/REORG.TODO/manual/examples/ofdlocks.c new file mode 100644 index 0000000000..42074105a8 --- /dev/null +++ b/REORG.TODO/manual/examples/ofdlocks.c @@ -0,0 +1,77 @@ +/* Open File Description Locks Usage Example + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, see <http://www.gnu.org/licenses/>. +*/ + +#define _GNU_SOURCE +#include <stdio.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> +#include <fcntl.h> +#include <pthread.h> + +#define FILENAME "/tmp/foo" +#define NUM_THREADS 3 +#define ITERATIONS 5 + +void * +thread_start (void *arg) +{ + int i, fd, len; + long tid = (long) arg; + char buf[256]; + struct flock lck = { + .l_whence = SEEK_SET, + .l_start = 0, + .l_len = 1, + }; + + fd = open ("/tmp/foo", O_RDWR | O_CREAT, 0666); + + for (i = 0; i < ITERATIONS; i++) + { + lck.l_type = F_WRLCK; + fcntl (fd, F_OFD_SETLKW, &lck); + + len = sprintf (buf, "%d: tid=%ld fd=%d\n", i, tid, fd); + + lseek (fd, 0, SEEK_END); + write (fd, buf, len); + fsync (fd); + + lck.l_type = F_UNLCK; + fcntl (fd, F_OFD_SETLK, &lck); + + /* sleep to ensure lock is yielded to another thread */ + usleep (1); + } + pthread_exit (NULL); +} + +int +main (int argc, char **argv) +{ + long i; + pthread_t threads[NUM_THREADS]; + + truncate (FILENAME, 0); + + for (i = 0; i < NUM_THREADS; i++) + pthread_create (&threads[i], NULL, thread_start, (void *) i); + + pthread_exit (NULL); + return 0; +} diff --git a/REORG.TODO/manual/examples/pipe.c b/REORG.TODO/manual/examples/pipe.c new file mode 100644 index 0000000000..adfa4658dc --- /dev/null +++ b/REORG.TODO/manual/examples/pipe.c @@ -0,0 +1,87 @@ +/* Creating a Pipe + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <sys/types.h> +#include <unistd.h> +#include <stdio.h> +#include <stdlib.h> + +/* Read characters from the pipe and echo them to @code{stdout}. */ + +void +read_from_pipe (int file) +{ + FILE *stream; + int c; + stream = fdopen (file, "r"); + while ((c = fgetc (stream)) != EOF) + putchar (c); + fclose (stream); +} + +/* Write some random text to the pipe. */ + +void +write_to_pipe (int file) +{ + FILE *stream; + stream = fdopen (file, "w"); + fprintf (stream, "hello, world!\n"); + fprintf (stream, "goodbye, world!\n"); + fclose (stream); +} + +int +main (void) +{ + pid_t pid; + int mypipe[2]; + +/*@group*/ + /* Create the pipe. */ + if (pipe (mypipe)) + { + fprintf (stderr, "Pipe failed.\n"); + return EXIT_FAILURE; + } +/*@end group*/ + + /* Create the child process. */ + pid = fork (); + if (pid == (pid_t) 0) + { + /* This is the child process. + Close other end first. */ + close (mypipe[1]); + read_from_pipe (mypipe[0]); + return EXIT_SUCCESS; + } + else if (pid < (pid_t) 0) + { + /* The fork failed. */ + fprintf (stderr, "Fork failed.\n"); + return EXIT_FAILURE; + } + else + { + /* This is the parent process. + Close other end first. */ + close (mypipe[0]); + write_to_pipe (mypipe[1]); + return EXIT_SUCCESS; + } +} diff --git a/REORG.TODO/manual/examples/popen.c b/REORG.TODO/manual/examples/popen.c new file mode 100644 index 0000000000..cc7617c65c --- /dev/null +++ b/REORG.TODO/manual/examples/popen.c @@ -0,0 +1,55 @@ +/* Pipe to a Subprocess + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <stdlib.h> + +void +write_data (FILE * stream) +{ + int i; + for (i = 0; i < 100; i++) + fprintf (stream, "%d\n", i); + if (ferror (stream)) + { + fprintf (stderr, "Output to stream failed.\n"); + exit (EXIT_FAILURE); + } +} + +/*@group*/ +int +main (void) +{ + FILE *output; + + output = popen ("more", "w"); + if (!output) + { + fprintf (stderr, + "incorrect parameters or too many files.\n"); + return EXIT_FAILURE; + } + write_data (output); + if (pclose (output) != 0) + { + fprintf (stderr, + "Could not run more or other error.\n"); + } + return EXIT_SUCCESS; +} +/*@end group*/ diff --git a/REORG.TODO/manual/examples/rprintf.c b/REORG.TODO/manual/examples/rprintf.c new file mode 100644 index 0000000000..e49a2c4fbf --- /dev/null +++ b/REORG.TODO/manual/examples/rprintf.c @@ -0,0 +1,84 @@ +/* Printf Extension Example + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <printf.h> + +/*@group*/ +typedef struct +{ + char *name; +} +Widget; +/*@end group*/ + +int +print_widget (FILE *stream, + const struct printf_info *info, + const void *const *args) +{ + const Widget *w; + char *buffer; + int len; + + /* Format the output into a string. */ + w = *((const Widget **) (args[0])); + len = asprintf (&buffer, "<Widget %p: %s>", w, w->name); + if (len == -1) + return -1; + + /* Pad to the minimum field width and print to the stream. */ + len = fprintf (stream, "%*s", + (info->left ? -info->width : info->width), + buffer); + + /* Clean up and return. */ + free (buffer); + return len; +} + + +int +print_widget_arginfo (const struct printf_info *info, size_t n, + int *argtypes) +{ + /* We always take exactly one argument and this is a pointer to the + structure.. */ + if (n > 0) + argtypes[0] = PA_POINTER; + return 1; +} + + +int +main (void) +{ + /* Make a widget to print. */ + Widget mywidget; + mywidget.name = "mywidget"; + + /* Register the print function for widgets. */ + register_printf_function ('W', print_widget, print_widget_arginfo); + + /* Now print the widget. */ + printf ("|%W|\n", &mywidget); + printf ("|%35W|\n", &mywidget); + printf ("|%-35W|\n", &mywidget); + + return 0; +} diff --git a/REORG.TODO/manual/examples/search.c b/REORG.TODO/manual/examples/search.c new file mode 100644 index 0000000000..c434c11f8c --- /dev/null +++ b/REORG.TODO/manual/examples/search.c @@ -0,0 +1,113 @@ +/* Searching and Sorting Example + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +/* Define an array of critters to sort. */ + +struct critter + { + const char *name; + const char *species; + }; + +struct critter muppets[] = + { + {"Kermit", "frog"}, + {"Piggy", "pig"}, + {"Gonzo", "whatever"}, + {"Fozzie", "bear"}, + {"Sam", "eagle"}, + {"Robin", "frog"}, + {"Animal", "animal"}, + {"Camilla", "chicken"}, + {"Sweetums", "monster"}, + {"Dr. Strangepork", "pig"}, + {"Link Hogthrob", "pig"}, + {"Zoot", "human"}, + {"Dr. Bunsen Honeydew", "human"}, + {"Beaker", "human"}, + {"Swedish Chef", "human"} + }; + +int count = sizeof (muppets) / sizeof (struct critter); + + + +/* This is the comparison function used for sorting and searching. */ + +int +critter_cmp (const void *v1, const void *v2) +{ + const struct critter *c1 = v1; + const struct critter *c2 = v2; + + return strcmp (c1->name, c2->name); +} + + +/* Print information about a critter. */ + +void +print_critter (const struct critter *c) +{ + printf ("%s, the %s\n", c->name, c->species); +} + + +/*@group*/ +/* Do the lookup into the sorted array. */ + +void +find_critter (const char *name) +{ + struct critter target, *result; + target.name = name; + result = bsearch (&target, muppets, count, sizeof (struct critter), + critter_cmp); + if (result) + print_critter (result); + else + printf ("Couldn't find %s.\n", name); +} +/*@end group*/ + +/* Main program. */ + +int +main (void) +{ + int i; + + for (i = 0; i < count; i++) + print_critter (&muppets[i]); + printf ("\n"); + + qsort (muppets, count, sizeof (struct critter), critter_cmp); + + for (i = 0; i < count; i++) + print_critter (&muppets[i]); + printf ("\n"); + + find_critter ("Kermit"); + find_critter ("Gonzo"); + find_critter ("Janice"); + + return 0; +} diff --git a/REORG.TODO/manual/examples/select.c b/REORG.TODO/manual/examples/select.c new file mode 100644 index 0000000000..16c54c0c63 --- /dev/null +++ b/REORG.TODO/manual/examples/select.c @@ -0,0 +1,58 @@ +/* Waiting for Input or Output + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +/*@group*/ +#include <errno.h> +#include <stdio.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/time.h> +/*@end group*/ + +/*@group*/ +int +input_timeout (int filedes, unsigned int seconds) +{ + fd_set set; + struct timeval timeout; +/*@end group*/ + + /* Initialize the file descriptor set. */ + FD_ZERO (&set); + FD_SET (filedes, &set); + + /* Initialize the timeout data structure. */ + timeout.tv_sec = seconds; + timeout.tv_usec = 0; + +/*@group*/ + /* @code{select} returns 0 if timeout, 1 if input available, -1 if error. */ + return TEMP_FAILURE_RETRY (select (FD_SETSIZE, + &set, NULL, NULL, + &timeout)); +} +/*@end group*/ + +/*@group*/ +int +main (void) +{ + fprintf (stderr, "select returned %d.\n", + input_timeout (STDIN_FILENO, 5)); + return 0; +} +/*@end group*/ diff --git a/REORG.TODO/manual/examples/setjmp.c b/REORG.TODO/manual/examples/setjmp.c new file mode 100644 index 0000000000..20b5064914 --- /dev/null +++ b/REORG.TODO/manual/examples/setjmp.c @@ -0,0 +1,49 @@ +/* Introduction to Non-Local Exits + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <setjmp.h> +#include <stdlib.h> +#include <stdio.h> + +jmp_buf main_loop; + +void +abort_to_main_loop (int status) +{ + longjmp (main_loop, status); +} + +int +main (void) +{ + while (1) + if (setjmp (main_loop)) + puts ("Back at main loop...."); + else + do_command (); +} + + +void +do_command (void) +{ + char buffer[128]; + if (fgets (buffer, 128, stdin) == NULL) + abort_to_main_loop (-1); + else + exit (EXIT_SUCCESS); +} diff --git a/REORG.TODO/manual/examples/sigh1.c b/REORG.TODO/manual/examples/sigh1.c new file mode 100644 index 0000000000..6d4a0752f3 --- /dev/null +++ b/REORG.TODO/manual/examples/sigh1.c @@ -0,0 +1,53 @@ +/* Signal Handlers that Return + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> + +/* This flag controls termination of the main loop. */ +volatile sig_atomic_t keep_going = 1; + +/* The signal handler just clears the flag and re-enables itself. */ +void +catch_alarm (int sig) +{ + keep_going = 0; + signal (sig, catch_alarm); +} + +void +do_stuff (void) +{ + puts ("Doing stuff while waiting for alarm...."); +} + +int +main (void) +{ + /* Establish a handler for SIGALRM signals. */ + signal (SIGALRM, catch_alarm); + + /* Set an alarm to go off in a little while. */ + alarm (2); + + /* Check the flag once in a while to see when to quit. */ + while (keep_going) + do_stuff (); + + return EXIT_SUCCESS; +} diff --git a/REORG.TODO/manual/examples/sigusr.c b/REORG.TODO/manual/examples/sigusr.c new file mode 100644 index 0000000000..51b44dcf03 --- /dev/null +++ b/REORG.TODO/manual/examples/sigusr.c @@ -0,0 +1,78 @@ +/* Using kill for Communication + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +/*@group*/ +#include <signal.h> +#include <stdio.h> +#include <sys/types.h> +#include <unistd.h> +/*@end group*/ + +/* When a @code{SIGUSR1} signal arrives, set this variable. */ +volatile sig_atomic_t usr_interrupt = 0; + +void +synch_signal (int sig) +{ + usr_interrupt = 1; +} + +/* The child process executes this function. */ +void +child_function (void) +{ + /* Perform initialization. */ + printf ("I'm here!!! My pid is %d.\n", (int) getpid ()); + + /* Let parent know you're done. */ + kill (getppid (), SIGUSR1); + + /* Continue with execution. */ + puts ("Bye, now...."); + exit (0); +} + +int +main (void) +{ + struct sigaction usr_action; + sigset_t block_mask; + pid_t child_id; + + /* Establish the signal handler. */ + sigfillset (&block_mask); + usr_action.sa_handler = synch_signal; + usr_action.sa_mask = block_mask; + usr_action.sa_flags = 0; + sigaction (SIGUSR1, &usr_action, NULL); + + /* Create the child process. */ + child_id = fork (); + if (child_id == 0) + child_function (); /* Does not return. */ + +/*@group*/ + /* Busy wait for the child to send a signal. */ + while (!usr_interrupt) + ; +/*@end group*/ + + /* Now continue execution. */ + puts ("That's all, folks!"); + + return 0; +} diff --git a/REORG.TODO/manual/examples/stpcpy.c b/REORG.TODO/manual/examples/stpcpy.c new file mode 100644 index 0000000000..a0dda1757a --- /dev/null +++ b/REORG.TODO/manual/examples/stpcpy.c @@ -0,0 +1,30 @@ +/* stpcpy example. + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <string.h> +#include <stdio.h> + +int +main (void) +{ + char buffer[10]; + char *to = buffer; + to = stpcpy (to, "foo"); + to = stpcpy (to, "bar"); + puts (buffer); + return 0; +} diff --git a/REORG.TODO/manual/examples/strdupa.c b/REORG.TODO/manual/examples/strdupa.c new file mode 100644 index 0000000000..c8e61bac16 --- /dev/null +++ b/REORG.TODO/manual/examples/strdupa.c @@ -0,0 +1,36 @@ +/* strdupa example. + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <paths.h> +#include <string.h> +#include <stdio.h> + +const char path[] = _PATH_STDPATH; + +int +main (void) +{ + char *wr_path = strdupa (path); + char *cp = strtok (wr_path, ":"); + + while (cp != NULL) + { + puts (cp); + cp = strtok (NULL, ":"); + } + return 0; +} diff --git a/REORG.TODO/manual/examples/strftim.c b/REORG.TODO/manual/examples/strftim.c new file mode 100644 index 0000000000..08eb22d539 --- /dev/null +++ b/REORG.TODO/manual/examples/strftim.c @@ -0,0 +1,48 @@ +/* Time Functions Example + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <time.h> +#include <stdio.h> + +#define SIZE 256 + +int +main (void) +{ + char buffer[SIZE]; + time_t curtime; + struct tm *loctime; + + /* Get the current time. */ + curtime = time (NULL); + + /* Convert it to local time representation. */ + loctime = localtime (&curtime); + + /* Print out the date and time in the standard format. */ + fputs (asctime (loctime), stdout); + +/*@group*/ + /* Print it out in a nice format. */ + strftime (buffer, SIZE, "Today is %A, %B %d.\n", loctime); + fputs (buffer, stdout); + strftime (buffer, SIZE, "The time is %I:%M %p.\n", loctime); + fputs (buffer, stdout); + + return 0; +} +/*@end group*/ diff --git a/REORG.TODO/manual/examples/subopt.c b/REORG.TODO/manual/examples/subopt.c new file mode 100644 index 0000000000..278b6dbbc1 --- /dev/null +++ b/REORG.TODO/manual/examples/subopt.c @@ -0,0 +1,95 @@ +/* Parsing of Suboptions Example + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> + +int do_all; +const char *type; +int read_size; +int write_size; +int read_only; + +enum +{ + RO_OPTION = 0, + RW_OPTION, + READ_SIZE_OPTION, + WRITE_SIZE_OPTION, + THE_END +}; + +const char *mount_opts[] = +{ + [RO_OPTION] = "ro", + [RW_OPTION] = "rw", + [READ_SIZE_OPTION] = "rsize", + [WRITE_SIZE_OPTION] = "wsize", + [THE_END] = NULL +}; + +int +main (int argc, char **argv) +{ + char *subopts, *value; + int opt; + + while ((opt = getopt (argc, argv, "at:o:")) != -1) + switch (opt) + { + case 'a': + do_all = 1; + break; + case 't': + type = optarg; + break; + case 'o': + subopts = optarg; + while (*subopts != '\0') + switch (getsubopt (&subopts, mount_opts, &value)) + { + case RO_OPTION: + read_only = 1; + break; + case RW_OPTION: + read_only = 0; + break; + case READ_SIZE_OPTION: + if (value == NULL) + abort (); + read_size = atoi (value); + break; + case WRITE_SIZE_OPTION: + if (value == NULL) + abort (); + write_size = atoi (value); + break; + default: + /* Unknown suboption. */ + printf ("Unknown suboption `%s'\n", value); + break; + } + break; + default: + abort (); + } + + /* Do the real work. */ + + return 0; +} diff --git a/REORG.TODO/manual/examples/swapcontext.c b/REORG.TODO/manual/examples/swapcontext.c new file mode 100644 index 0000000000..3747230c31 --- /dev/null +++ b/REORG.TODO/manual/examples/swapcontext.c @@ -0,0 +1,116 @@ +/* Complete Context Control + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <ucontext.h> +#include <sys/time.h> + +/* Set by the signal handler. */ +static volatile int expired; + +/* The contexts. */ +static ucontext_t uc[3]; + +/* We do only a certain number of switches. */ +static int switches; + + +/* This is the function doing the work. It is just a + skeleton, real code has to be filled in. */ +static void +f (int n) +{ + int m = 0; + while (1) + { + /* This is where the work would be done. */ + if (++m % 100 == 0) + { + putchar ('.'); + fflush (stdout); + } + + /* Regularly the @var{expire} variable must be checked. */ + if (expired) + { + /* We do not want the program to run forever. */ + if (++switches == 20) + return; + + printf ("\nswitching from %d to %d\n", n, 3 - n); + expired = 0; + /* Switch to the other context, saving the current one. */ + swapcontext (&uc[n], &uc[3 - n]); + } + } +} + +/* This is the signal handler which simply set the variable. */ +void +handler (int signal) +{ + expired = 1; +} + + +int +main (void) +{ + struct sigaction sa; + struct itimerval it; + char st1[8192]; + char st2[8192]; + + /* Initialize the data structures for the interval timer. */ + sa.sa_flags = SA_RESTART; + sigfillset (&sa.sa_mask); + sa.sa_handler = handler; + it.it_interval.tv_sec = 0; + it.it_interval.tv_usec = 1; + it.it_value = it.it_interval; + + /* Install the timer and get the context we can manipulate. */ + if (sigaction (SIGPROF, &sa, NULL) < 0 + || setitimer (ITIMER_PROF, &it, NULL) < 0 + || getcontext (&uc[1]) == -1 + || getcontext (&uc[2]) == -1) + abort (); + + /* Create a context with a separate stack which causes the + function @code{f} to be call with the parameter @code{1}. + Note that the @code{uc_link} points to the main context + which will cause the program to terminate once the function + return. */ + uc[1].uc_link = &uc[0]; + uc[1].uc_stack.ss_sp = st1; + uc[1].uc_stack.ss_size = sizeof st1; + makecontext (&uc[1], (void (*) (void)) f, 1, 1); + + /* Similarly, but @code{2} is passed as the parameter to @code{f}. */ + uc[2].uc_link = &uc[0]; + uc[2].uc_stack.ss_sp = st2; + uc[2].uc_stack.ss_size = sizeof st2; + makecontext (&uc[2], (void (*) (void)) f, 1, 2); + + /* Start running. */ + swapcontext (&uc[0], &uc[1]); + putchar ('\n'); + + return 0; +} diff --git a/REORG.TODO/manual/examples/termios.c b/REORG.TODO/manual/examples/termios.c new file mode 100644 index 0000000000..8ac2f626d5 --- /dev/null +++ b/REORG.TODO/manual/examples/termios.c @@ -0,0 +1,77 @@ +/* Noncanonical Mode Example + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <unistd.h> +#include <stdio.h> +#include <stdlib.h> +#include <termios.h> + +/* Use this variable to remember original terminal attributes. */ + +struct termios saved_attributes; + +void +reset_input_mode (void) +{ + tcsetattr (STDIN_FILENO, TCSANOW, &saved_attributes); +} + +void +set_input_mode (void) +{ + struct termios tattr; + char *name; + + /* Make sure stdin is a terminal. */ + if (!isatty (STDIN_FILENO)) + { + fprintf (stderr, "Not a terminal.\n"); + exit (EXIT_FAILURE); + } + + /* Save the terminal attributes so we can restore them later. */ + tcgetattr (STDIN_FILENO, &saved_attributes); + atexit (reset_input_mode); + +/*@group*/ + /* Set the funny terminal modes. */ + tcgetattr (STDIN_FILENO, &tattr); + tattr.c_lflag &= ~(ICANON|ECHO); /* Clear ICANON and ECHO. */ + tattr.c_cc[VMIN] = 1; + tattr.c_cc[VTIME] = 0; + tcsetattr (STDIN_FILENO, TCSAFLUSH, &tattr); +} +/*@end group*/ + +int +main (void) +{ + char c; + + set_input_mode (); + + while (1) + { + read (STDIN_FILENO, &c, 1); + if (c == '\004') /* @kbd{C-d} */ + break; + else + putchar (c); + } + + return EXIT_SUCCESS; +} diff --git a/REORG.TODO/manual/examples/testopt.c b/REORG.TODO/manual/examples/testopt.c new file mode 100644 index 0000000000..1cb53352eb --- /dev/null +++ b/REORG.TODO/manual/examples/testopt.c @@ -0,0 +1,72 @@ +/* Example of Parsing Arguments with getopt. + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +/*@group*/ +#include <ctype.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> + +int +main (int argc, char **argv) +{ + int aflag = 0; + int bflag = 0; + char *cvalue = NULL; + int index; + int c; + + opterr = 0; +/*@end group*/ + +/*@group*/ + while ((c = getopt (argc, argv, "abc:")) != -1) + switch (c) + { + case 'a': + aflag = 1; + break; + case 'b': + bflag = 1; + break; + case 'c': + cvalue = optarg; + break; + case '?': + if (optopt == 'c') + fprintf (stderr, "Option -%c requires an argument.\n", optopt); + else if (isprint (optopt)) + fprintf (stderr, "Unknown option `-%c'.\n", optopt); + else + fprintf (stderr, + "Unknown option character `\\x%x'.\n", + optopt); + return 1; + default: + abort (); + } +/*@end group*/ + +/*@group*/ + printf ("aflag = %d, bflag = %d, cvalue = %s\n", + aflag, bflag, cvalue); + + for (index = optind; index < argc; index++) + printf ("Non-option argument %s\n", argv[index]); + return 0; +} +/*@end group*/ diff --git a/REORG.TODO/manual/examples/testpass.c b/REORG.TODO/manual/examples/testpass.c new file mode 100644 index 0000000000..12c44f3028 --- /dev/null +++ b/REORG.TODO/manual/examples/testpass.c @@ -0,0 +1,43 @@ +/* Verify a password. + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <string.h> +#include <unistd.h> +#include <crypt.h> + +int +main(void) +{ + /* Hashed form of "GNU libc manual". */ + const char *const pass = "$1$/iSaq7rB$EoUw5jJPPvAPECNaaWzMK/"; + + char *result; + int ok; + +/*@group*/ + /* Read in the user's password and encrypt it, + passing the expected password in as the salt. */ + result = crypt(getpass("Password:"), pass); +/*@end group*/ + + /* Test the result. */ + ok = strcmp (result, pass) == 0; + + puts(ok ? "Access granted." : "Access denied."); + return ok ? 0 : 1; +} diff --git a/REORG.TODO/manual/examples/timeval_subtract.c b/REORG.TODO/manual/examples/timeval_subtract.c new file mode 100644 index 0000000000..554dc77f40 --- /dev/null +++ b/REORG.TODO/manual/examples/timeval_subtract.c @@ -0,0 +1,44 @@ +/* struct timeval subtraction. + Copyright (C) 1991-2017 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, if not, see <http://www.gnu.org/licenses/>. +*/ + +/* Subtract the `struct timeval' values X and Y, + storing the result in RESULT. + Return 1 if the difference is negative, otherwise 0. */ + +int +timeval_subtract (struct timeval *result, struct timeval *x, struct timeval *y) +{ + /* Perform the carry for the later subtraction by updating @var{y}. */ + if (x->tv_usec < y->tv_usec) { + int nsec = (y->tv_usec - x->tv_usec) / 1000000 + 1; + y->tv_usec -= 1000000 * nsec; + y->tv_sec += nsec; + } + if (x->tv_usec - y->tv_usec > 1000000) { + int nsec = (x->tv_usec - y->tv_usec) / 1000000; + y->tv_usec += 1000000 * nsec; + y->tv_sec -= nsec; + } + + /* Compute the time remaining to wait. + @code{tv_usec} is certainly positive. */ + result->tv_sec = x->tv_sec - y->tv_sec; + result->tv_usec = x->tv_usec - y->tv_usec; + + /* Return 1 if result is negative. */ + return x->tv_sec < y->tv_sec; +} |