/* See LICENSE file for copyright and license details. */ #include #include #include #include #include #include "text.h" #include "util.h" enum { NARGS = 5000 }; static int inputc(void); static void deinputc(int); static void fillbuf(int); static void eatspace(void); static int parsequote(int); static void parseescape(void); static char *poparg(void); static void pusharg(char *); static int runcmd(void); static char **cmd; static char *argb; static size_t argbsz = 1; static size_t argbpos; static int rflag = 0; static void usage(void) { eprintf("usage: %s [-r] [cmd [arg...]]\n", argv0); } int main(int argc, char *argv[]) { long argsz, argmaxsz; char *arg; int i; ARGBEGIN { case 'r': rflag = 1; break; default: usage(); } ARGEND; argmaxsz = sysconf(_SC_ARG_MAX); if (argmaxsz < 0) eprintf("sysconf:"); /* Leave some room for environment variables */ argmaxsz -= 4 * 1024; cmd = malloc(NARGS * sizeof(*cmd)); if (!cmd) eprintf("malloc:"); argb = malloc(argbsz); if (!argb) eprintf("malloc:"); do { argsz = 0; i = 0; if (argc > 0) { for (; i < argc; i++) { cmd[i] = strdup(argv[i]); argsz += strlen(cmd[i]) + 1; } } else { cmd[i] = strdup("/bin/echo"); argsz += strlen(cmd[i]) + 1; i++; } while ((arg = poparg())) { if (argsz + strlen(arg) + 1 > argmaxsz || i >= NARGS - 1) { pusharg(arg); break; } cmd[i] = strdup(arg); argsz += strlen(cmd[i]) + 1; i++; } cmd[i] = NULL; if (i == 1 && rflag == 1) ; else if (runcmd() == -1) arg = NULL; for (; i >= 0; i--) free(cmd[i]); } while (arg); free(argb); free(cmd); return 0; } static int inputc(void) { int ch; ch = getc(stdin); if (ch == EOF && ferror(stdin)) eprintf("stdin: read error:"); return ch; } static void deinputc(int ch) { ungetc(ch, stdin); } static void fillbuf(int ch) { if (argbpos >= argbsz) { argbsz *= 2; argb = realloc(argb, argbsz); if (!argb) eprintf("realloc:"); } argb[argbpos] = ch; } static void eatspace(void) { int ch; while ((ch = inputc()) != EOF) { switch (ch) { case ' ': case '\t': case '\n': break; default: deinputc(ch); return; } } } static int parsequote(int q) { int ch; while ((ch = inputc()) != EOF) { if (ch == q) { fillbuf('\0'); return 0; } if (ch != '\n') { fillbuf(ch); argbpos++; } } return -1; } static void parseescape(void) { int ch; if ((ch = inputc()) != EOF) { fillbuf(ch); argbpos++; } } static char * poparg(void) { int ch; argbpos = 0; eatspace(); while ((ch = inputc()) != EOF) { switch (ch) { case ' ': case '\t': case '\n': fillbuf('\0'); deinputc(ch); return argb; case '\'': if (parsequote('\'') == -1) enprintf(EXIT_FAILURE, "unterminated single quote\n"); break; case '\"': if (parsequote('\"') == -1) enprintf(EXIT_FAILURE, "unterminated double quote\n"); break; case '\\': parseescape(); break; default: fillbuf(ch); argbpos++; break; } } if (argbpos > 0) { fillbuf('\0'); return argb; } return NULL; } static void pusharg(char *arg) { char *p; for (p = &arg[strlen(arg) - 1]; p >= arg; p--) deinputc(*p); } static int runcmd(void) { pid_t pid; int status; pid = fork(); if (pid < 0) eprintf("fork:"); if (pid == 0) { execvp(*cmd, cmd); eprintf("execvp %s:", *cmd); } wait(&status); if (WIFEXITED(status) && WEXITSTATUS(status) == 255) return -1; return 0; }