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/* See LICENSE file for copyright and license details. */
#include <sys/wait.h>
#include <errno.h>
#include <limits.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "util.h"
#define NARGS 10000
static int inputc(void);
static void fillargbuf(int);
static int eatspace(void);
static int parsequote(int);
static int parseescape(void);
static char *poparg(void);
static void waitchld(void);
static void spawn(void);
static size_t argbsz;
static size_t argbpos;
static size_t maxargs = 0;
static int nerrors = 0;
static int rflag = 0, nflag = 0, tflag = 0, xflag = 0;
static char *argb;
static char *cmd[NARGS];
static char *eofstr;
static int
inputc(void)
{
int ch;
ch = getc(stdin);
if (ch == EOF && ferror(stdin))
eprintf("getc <stdin>:");
return ch;
}
static void
fillargbuf(int ch)
{
if (argbpos >= argbsz) {
argbsz = argbpos == 0 ? 1 : argbsz * 2;
argb = erealloc(argb, argbsz);
}
argb[argbpos] = ch;
}
static int
eatspace(void)
{
int ch;
while ((ch = inputc()) != EOF) {
switch (ch) {
case ' ': case '\t': case '\n':
break;
default:
ungetc(ch, stdin);
return ch;
}
}
return -1;
}
static int
parsequote(int q)
{
int ch;
while ((ch = inputc()) != EOF) {
if (ch == q)
return 0;
if (ch != '\n') {
fillargbuf(ch);
argbpos++;
}
}
return -1;
}
static int
parseescape(void)
{
int ch;
if ((ch = inputc()) != EOF) {
fillargbuf(ch);
argbpos++;
return ch;
}
return -1;
}
static char *
poparg(void)
{
int ch;
argbpos = 0;
if (eatspace() < 0)
return NULL;
while ((ch = inputc()) != EOF) {
switch (ch) {
case ' ': case '\t': case '\n':
goto out;
case '\'':
if (parsequote('\'') < 0)
eprintf("unterminated single quote\n");
break;
case '\"':
if (parsequote('\"') < 0)
eprintf("unterminated double quote\n");
break;
case '\\':
if (parseescape() < 0)
eprintf("backslash at EOF\n");
break;
default:
fillargbuf(ch);
argbpos++;
break;
}
}
out:
fillargbuf('\0');
return (eofstr && !strcmp(argb, eofstr)) ? NULL : argb;
}
static void
waitchld(void)
{
int status;
wait(&status);
if (WIFEXITED(status)) {
if (WEXITSTATUS(status) == 255)
exit(124);
if (WEXITSTATUS(status) == 127 ||
WEXITSTATUS(status) == 126)
exit(WEXITSTATUS(status));
if (status)
nerrors++;
}
if (WIFSIGNALED(status))
exit(125);
}
static void
spawn(void)
{
int savederrno;
int first = 1;
char **p;
if (tflag) {
for (p = cmd; *p; p++) {
if (!first)
fputc(' ', stderr);
fputs(*p, stderr);
first = 0;
}
fputc('\n', stderr);
}
switch (fork()) {
case -1:
eprintf("fork:");
case 0:
execvp(*cmd, cmd);
savederrno = errno;
weprintf("execvp %s:", *cmd);
_exit(126 + (savederrno == ENOENT));
}
waitchld();
}
static void
usage(void)
{
eprintf("usage: %s [-rtx] [-E eofstr] [-n num] [-s num] "
"[cmd [arg ...]]\n", argv0);
}
int
main(int argc, char *argv[])
{
int ret = 0, leftover = 0, i;
size_t argsz, argmaxsz;
size_t arglen, a;
char *arg = "";
if ((argmaxsz = sysconf(_SC_ARG_MAX)) == (size_t)-1)
argmaxsz = _POSIX_ARG_MAX;
/* Leave some room for environment variables */
argmaxsz -= 4096;
ARGBEGIN {
case 'n':
nflag = 1;
maxargs = estrtonum(EARGF(usage()), 1, MIN(SIZE_MAX, LLONG_MAX));
break;
case 'r':
rflag = 1;
break;
case 's':
argmaxsz = estrtonum(EARGF(usage()), 1, MIN(SIZE_MAX, LLONG_MAX));
break;
case 't':
tflag = 1;
break;
case 'x':
xflag = 1;
break;
case 'E':
eofstr = EARGF(usage());
break;
default:
usage();
} ARGEND
do {
argsz = 0; i = 0; a = 0;
if (argc) {
for (; i < argc; i++) {
cmd[i] = estrdup(argv[i]);
argsz += strlen(cmd[i]) + 1;
}
} else {
cmd[i] = estrdup("/bin/echo");
argsz += strlen("/bin/echo") + 1;
i++;
}
while (leftover || (arg = poparg())) {
arglen = strlen(arg);
if (argsz + arglen >= argmaxsz || i >= NARGS - 1) {
if (arglen >= argmaxsz) {
weprintf("insufficient argument space\n");
if (xflag)
exit(1);
}
leftover = 1;
break;
}
cmd[i] = estrdup(arg);
argsz += arglen + 1;
i++;
a++;
leftover = 0;
if (nflag && a >= maxargs)
break;
}
cmd[i] = NULL;
if (a >= maxargs && nflag)
spawn();
else if (!a || (i == 1 && rflag))
;
else
spawn();
for (; i >= 0; i--)
free(cmd[i]);
} while (arg);
free(argb);
if (nerrors || (fshut(stdin, "<stdin>") | fshut(stdout, "<stdout>")))
ret = 123;
return ret;
}