diff options
Diffstat (limited to 'posix')
| -rw-r--r-- | posix/wordexp.c | 263 |
1 files changed, 175 insertions, 88 deletions
diff --git a/posix/wordexp.c b/posix/wordexp.c index 302cf0884f..fd6ce113b2 100644 --- a/posix/wordexp.c +++ b/posix/wordexp.c @@ -174,8 +174,8 @@ w_addword (wordexp_t *pwordexp, char *word) if (new_wordv != NULL) { pwordexp->we_wordv = new_wordv; - pwordexp->we_wordv[pwordexp->we_wordc++] = word; - pwordexp->we_wordv[pwordexp->we_wordc] = NULL; + pwordexp->we_wordv[pwordexp->we_offs + pwordexp->we_wordc++] = word; + pwordexp->we_wordv[pwordexp->we_offs + pwordexp->we_wordc] = NULL; return 0; } @@ -299,35 +299,51 @@ parse_tilde (char **word, size_t *word_length, size_t *max_length, uid_t uid; struct passwd pwd, *tpwd; int buflen = 1000; - char* buffer = __alloca (buflen); + char* home; + char* buffer; int result; - uid = __getuid (); - - while ((result = __getpwuid_r (uid, &pwd, buffer, buflen, &tpwd)) != 0 - && errno == ERANGE) - { - buflen += 1000; - buffer = __alloca (buflen); - } + /* POSIX.2 says ~ expands to $HOME and if HOME is unset the + results are unspecified. We do a lookup on the uid if + HOME is unset. */ - if (result == 0 && tpwd != NULL && pwd.pw_dir != NULL) + home = getenv ("HOME"); + if (home != NULL) { - *word = w_addstr (*word, word_length, max_length, pwd.pw_dir); + *word = w_addstr (*word, word_length, max_length, home); if (*word == NULL) return WRDE_NOSPACE; } else { - *word = w_addchar (*word, word_length, max_length, '~'); - if (*word == NULL) - return WRDE_NOSPACE; + uid = __getuid (); + buffer = __alloca (buflen); + + while ((result = __getpwuid_r (uid, &pwd, buffer, buflen, &tpwd)) != 0 + && errno == ERANGE) + { + buflen += 1000; + buffer = __alloca (buflen); + } + + if (result == 0 && tpwd != NULL && pwd.pw_dir != NULL) + { + *word = w_addstr (*word, word_length, max_length, pwd.pw_dir); + if (*word == NULL) + return WRDE_NOSPACE; + } + else + { + *word = w_addchar (*word, word_length, max_length, '~'); + if (*word == NULL) + return WRDE_NOSPACE; + } } } else { /* Look up user name in database to get home directory */ - char *user = __strndup (&words[1 + *offset], i - *offset); + char *user = __strndup (&words[1 + *offset], i - (1 + *offset)); struct passwd pwd, *tpwd; int buflen = 1000; char* buffer = __alloca (buflen); @@ -806,6 +822,44 @@ parse_arith (char **word, size_t *word_length, size_t *max_length, return WRDE_SYNTAX; } +/* Function called by child process in exec_comm() */ +static void +internal_function +exec_comm_child (char *comm, int *fildes, int showerr, int noexec) +{ + const char *args[4] = { _PATH_BSHELL, "-c", comm, NULL }; + + /* Execute the command, or just check syntax? */ + if (noexec) + args[1] = "-nc"; + + /* Redirect output. */ + __dup2 (fildes[1], 1); + __close (fildes[1]); + + /* Redirect stderr to /dev/null if we have to. */ + if (showerr == 0) + { + int fd; + __close (2); + fd = __open (_PATH_DEVNULL, O_WRONLY); + if (fd >= 0 && fd != 2) + { + __dup2 (fd, 2); + __close (fd); + } + } + + /* Make sure the subshell doesn't field-split on our behalf. */ + unsetenv ("IFS"); + + __close (fildes[0]); + __execve (_PATH_BSHELL, (char *const *) args, __environ); + + /* Bad. What now? */ + abort (); +} + /* Function to execute a command and retrieve the results */ /* pwordexp contains NULL if field-splitting is forbidden */ static int @@ -818,6 +872,8 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, int bufsize = 128; int buflen; int i; + int status = 0; + size_t maxnewlines = 0; char *buffer; pid_t pid; @@ -838,36 +894,7 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, } if (pid == 0) - { - /* Child */ - const char *args[4] = { _PATH_BSHELL, "-c", comm, NULL }; - - /* Redirect output. */ - __dup2 (fildes[1], 1); - __close (fildes[1]); - - /* Redirect stderr to /dev/null if we have to. */ - if ((flags & WRDE_SHOWERR) == 0) - { - int fd; - __close (2); - fd = __open (_PATH_DEVNULL, O_WRONLY); - if (fd >= 0 && fd != 2) - { - __dup2 (fd, 2); - __close (fd); - } - } - - /* Make sure the subshell doesn't field-split on our behalf. */ - unsetenv ("IFS"); - - __close (fildes[0]); - __execve (_PATH_BSHELL, (char *const *) args, __environ); - - /* Bad. What now? */ - abort (); - } + exec_comm_child(comm, fildes, (flags & WRDE_SHOWERR), 0); /* Parent */ @@ -875,18 +902,20 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, buffer = __alloca (bufsize); if (!pwordexp) - { /* Quoted - no field splitting */ - + /* Quoted - no field splitting */ + { while (1) { if ((buflen = __read (fildes[0], buffer, bufsize)) < 1) { - if (__waitpid (pid, NULL, WNOHANG) == 0) + if (__waitpid (pid, &status, WNOHANG) == 0) continue; if ((buflen = __read (fildes[0], buffer, bufsize)) < 1) break; } + maxnewlines += buflen; + *word = w_addmem (*word, word_length, max_length, buffer, buflen); if (*word == NULL) goto no_space; @@ -900,15 +929,16 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, * 0 when searching for first character in a field not IFS white space * 1 when copying the text of a field * 2 when searching for possible non-whitespace IFS + * 3 when searching for non-newline after copying field */ while (1) { if ((buflen = __read (fildes[0], buffer, bufsize)) < 1) { - if (__waitpid (pid, NULL, WNOHANG) == 0) + if (__waitpid (pid, &status, WNOHANG) == 0) continue; - if ((__read (fildes[0], buffer, bufsize)) < 1) + if ((buflen = __read (fildes[0], buffer, bufsize)) < 1) break; } @@ -938,29 +968,64 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, } else { - /* Current character is IFS white space */ + if (buffer[i] == '\n') + { + /* Current character is (IFS) newline */ - /* If not copying a field, ignore it */ - if (copying != 1) - continue; + /* If copying a field, this is the end of it, + but maybe all that's left is trailing newlines. + So start searching for a non-newline. */ + if (copying == 1) + copying = 3; - /* End of field (search for non-ws IFS afterwards) */ - copying = 2; + continue; + } + else + { + /* Current character is IFS white space, but + not a newline */ + + /* If not either copying a field or searching + for non-newline after a field, ignore it */ + if (copying != 1 && copying != 3) + continue; + + /* End of field (search for non-ws IFS afterwards) */ + copying = 2; + } } - /* First IFS white space, or IFS non-whitespace. + /* First IFS white space (non-newline), or IFS non-whitespace. * Delimit the field. Nulls are converted by w_addword. */ if (w_addword (pwordexp, *word) == WRDE_NOSPACE) goto no_space; *word = w_newword (word_length, max_length); + + maxnewlines = 0; /* fall back round the loop.. */ } else { /* Not IFS character */ + + if (copying == 3) + { + /* Nothing but (IFS) newlines since the last field, + so delimit it here before starting new word */ + if (w_addword (pwordexp, *word) == WRDE_NOSPACE) + goto no_space; + + *word = w_newword (word_length, max_length); + } + copying = 1; + if (buffer[i] == '\n') /* happens if newline not in IFS */ + maxnewlines++; + else + maxnewlines = 0; + *word = w_addchar (*word, word_length, max_length, buffer[i]); if (*word == NULL) @@ -970,8 +1035,11 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, } } - /* Bash chops off trailing newlines, which seems sensible. */ - while (*word_length > 0 && (*word)[*word_length - 1] == '\n') + /* Chop off trailing newlines (required by POSIX.2) */ + /* Ensure we don't go back further than the beginning of the + substitution (i.e. remove maxnewlines bytes at most) */ + while (maxnewlines-- != 0 && + *word_length > 0 && (*word)[*word_length - 1] == '\n') { (*word)[--*word_length] = '\0'; @@ -986,6 +1054,26 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, } __close (fildes[0]); + + /* Check for syntax error (re-execute but with "-n" flag) */ + if (buflen < 1 && status != 0) + { + if ((pid = __fork ()) < 0) + { + /* Bad */ + return WRDE_NOSPACE; + } + + if (pid == 0) + { + fildes[0] = fildes[1] = -1; + exec_comm_child(comm, fildes, 0, 1); + } + + if (__waitpid (pid, &status, 0) == pid && status != 0) + return WRDE_SYNTAX; + } + return 0; no_space: @@ -2109,7 +2197,6 @@ wordfree (wordexp_t *pwordexp) int wordexp (const char *words, wordexp_t *pwordexp, int flags) { - size_t wordv_offset; size_t words_offset; size_t word_length; size_t max_length; @@ -2117,42 +2204,41 @@ wordexp (const char *words, wordexp_t *pwordexp, int flags) int error; char *ifs; char ifs_white[4]; - char **old_wordv = pwordexp->we_wordv; - size_t old_wordc = (flags & WRDE_REUSE) ? pwordexp->we_wordc : 0; + wordexp_t old_word = *pwordexp; if (flags & WRDE_REUSE) { /* Minimal implementation of WRDE_REUSE for now */ wordfree (pwordexp); - old_wordv = NULL; + old_word.we_wordv = NULL; } - if (flags & WRDE_DOOFFS) + if ((flags & WRDE_APPEND) == 0) { - pwordexp->we_wordv = calloc (1 + pwordexp->we_offs, sizeof (char *)); - if (pwordexp->we_wordv == NULL) + pwordexp->we_wordc = 0; + + if (flags & WRDE_DOOFFS) { - error = WRDE_NOSPACE; - goto do_error; + pwordexp->we_wordv = calloc (1 + pwordexp->we_offs, sizeof (char *)); + if (pwordexp->we_wordv == NULL) + { + error = WRDE_NOSPACE; + goto do_error; + } } - } - else - { - pwordexp->we_wordv = calloc (1, sizeof (char *)); - if (pwordexp->we_wordv == NULL) + else { - error = WRDE_NOSPACE; - goto do_error; - } + pwordexp->we_wordv = calloc (1, sizeof (char *)); + if (pwordexp->we_wordv == NULL) + { + error = WRDE_NOSPACE; + goto do_error; + } - pwordexp->we_offs = 0; + pwordexp->we_offs = 0; + } } - if ((flags & WRDE_APPEND) == 0) - pwordexp->we_wordc = 0; - - wordv_offset = pwordexp->we_offs + pwordexp->we_wordc; - /* Find out what the field separators are. * There are two types: whitespace and non-whitespace. */ @@ -2333,7 +2419,7 @@ wordexp (const char *words, wordexp_t *pwordexp, int flags) do_error: /* Error: * free memory used (unless error is WRDE_NOSPACE), and - * set we_wordc and wd_wordv back to what they were. + * set pwordexp members back to what they were. */ if (word != NULL) @@ -2342,8 +2428,9 @@ do_error: if (error == WRDE_NOSPACE) return WRDE_NOSPACE; - wordfree (pwordexp); - pwordexp->we_wordv = old_wordv; - pwordexp->we_wordc = old_wordc; + if ((flags & WRDE_APPEND) == 0) + wordfree (pwordexp); + + *pwordexp = old_word; return error; } |