From 1575f68ee189304c8a158786e979f5e5cde3a20a Mon Sep 17 00:00:00 2001 From: Christian Neukirchen Date: Thu, 10 Dec 2015 17:11:59 +0100 Subject: implement -N0 to fill up with arguments up to _SC_ARG_MAX, revamp allocation --- xe.c | 167 +++++++++++++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 118 insertions(+), 49 deletions(-) (limited to 'xe.c') diff --git a/xe.c b/xe.c index 2ccec37..42ca3b9 100644 --- a/xe.c +++ b/xe.c @@ -11,6 +11,7 @@ #include #include +#include #include #include #include @@ -22,7 +23,6 @@ static char delim = '\n'; static char default_replace[] = "{}"; static char *replace = default_replace; static char *argsep; -static char **args; static char *sflag; static int maxatonce = 1; @@ -31,14 +31,16 @@ static int runjobs = 0; static int Rflag, Aflag, aflag, kflag, nflag, vflag; static long iterations = 0; -static char * -xstrdup(const char *s) -{ - char *d = strdup(s); - if (!d) - exit(1); - return d; -} +static size_t argmax; +static int push_overflowed; + +static char *buf; +static size_t buflen; +static size_t bufcap; + +static char **args; +static size_t argslen; +static size_t argscap; static char *getarg_line = 0; static size_t getarg_len = 0; @@ -48,7 +50,7 @@ getarg() { if (aflag || Aflag) { if (args && *args) - return xstrdup(*args++); + return *args++; else return 0; } @@ -63,7 +65,7 @@ getarg() if (getarg_line[read-1] == delim) // strip delimiter getarg_line[read-1] = 0; - return xstrdup(getarg_line); + return getarg_line; } static int @@ -120,33 +122,80 @@ shquote(const char *s) } static int -trace(char *cmd[]) +trace() { - int i; - - for (i = 0; cmd[i]; i++) { + size_t i; + + for (i = 0; i < argslen; i++) { if (i > 0) printf(" "); - shquote(cmd[i]); + shquote(args[i]); } printf("\n"); return 0; } +static void +scanargs() +{ + char *s = buf; + size_t i; + + if (argslen + 1 >= argscap) { + while (argslen + 1 >= argscap) + argscap *= 2; + args = realloc(args, sizeof args[0] * argscap); + if (!args) + exit(1); + } + + for (i = 0; i < argslen; i++) { + args[i] = s; + s += strlen(s) + 1; + } + args[i] = 0; +} + static int -run(char *cmd[]) +pusharg(const char *a) +{ + size_t l = strlen(a) + 1; // including nul + + if (buflen >= argmax - l) { + push_overflowed = 1; + return 0; + } + + if (buflen + l > bufcap) { + bufcap *= 2; + buf = realloc(buf, bufcap); + if (!args) + exit(1); + } + + memcpy(buf + buflen, a, l); + buflen += l; + argslen++; + + return 1; +} + +static int +run() { pid_t pid; - int i; if (runjobs >= maxjobs) mywait(); runjobs++; iterations++; + scanargs(); + if (vflag || nflag) - trace(cmd); + trace(); + if (nflag) { runjobs--; return 0; @@ -163,18 +212,15 @@ run(char *cmd[]) if (dup2(fd, 0) != 0) exit(1); close(fd); - execvp(cmd[0], cmd); + execvp(args[0], args); } - fprintf(stderr, "xe: %s: %s\n", cmd[0], strerror(errno)); + fprintf(stderr, "xe: %s: %s\n", args[0], strerror(errno)); exit(errno == ENOENT ? 127 : 126); } if (pid < 0) exit(126); - for (i = 0; cmd[i]; i++) - free(cmd[i]); - return 0; } @@ -183,7 +229,20 @@ main(int argc, char *argv[]) { char c; int i, cmdend; - char *arg, **cmd; + char *arg; + + bufcap = 4096; + buf = malloc(bufcap); + + argscap = 4096; + args = malloc(sizeof args[0] * argscap); + + if (!buf || !args) + exit(1); + + argmax = sysconf(_SC_ARG_MAX); + if (argmax <= 0) + argmax = _POSIX_ARG_MAX; while ((c = getopt(argc, argv, "+0A:I:N:Raj:kns:v")) != -1) switch(c) { @@ -230,22 +289,20 @@ main(int argc, char *argv[]) } } - cmd = calloc(argc-optind+maxatonce+1+ - (optind==cmdend ? 2 : 0)+(sflag ? 4 : 0), sizeof (char *)); - if (!cmd) - exit(1); - while ((arg = getarg())) { - int l = 0; +keeparg: + buflen = 0; + argslen = 0; + push_overflowed = 0; if (sflag) { - cmd[l++] = xstrdup("/bin/sh"); - cmd[l++] = xstrdup("-c"); - cmd[l++] = xstrdup(sflag); - cmd[l++] = xstrdup("-"); + pusharg("/bin/sh"); + pusharg("-c"); + pusharg(sflag); + pusharg("-"); } else if (optind == cmdend) { - cmd[l++] = xstrdup("printf"); - cmd[l++] = xstrdup("%s\\n"); + pusharg("printf"); + pusharg("%s\\n"); } if (maxatonce == 1) { @@ -253,34 +310,46 @@ main(int argc, char *argv[]) int substituted = 0; for (i = optind; i < cmdend; i++) { if (strcmp(argv[i], replace) == 0) { - cmd[l++] = arg; + pusharg(arg); substituted = 1; } else { - cmd[l++] = xstrdup(argv[i]); + pusharg(argv[i]); } } if (!substituted) - cmd[l++] = arg; + pusharg(arg); } else { // just append to cmd for (i = optind; i < cmdend; i++) - cmd[l++] = xstrdup(argv[i]); - cmd[l++] = arg; - for (i = 0; i < maxatonce - 1; i++) { - cmd[l] = getarg(); - if (!cmd[l++]) - break; + pusharg(argv[i]); + pusharg(arg); + if (!push_overflowed) { + for (i = 0; maxatonce < 1 || i < maxatonce - 1; i++) { + arg = getarg(); + if (!arg) + break; + if (!pusharg(arg)) { + run(); + goto keeparg; + } + } } } - cmd[l] = 0; - run(cmd); + + if (push_overflowed) { + fprintf(stderr, "xe: fixed argument list too long\n"); + exit(1); + } + run(); } while (mywait()) ; - free(cmd); + free(buf); + free(args); free(getarg_line); + if (Rflag && iterations == 0) return 122; return 0; -- cgit 1.4.1