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/*
* deep_helper.c – test helper for pwd's deep-path test
*
* Usage: deep_helper <depth> <segment> <pwd_binary>
*
* Creates `depth` nested directories each named `segment`, navigates
* into the deepest one using chdir(2) (not the shell's cd builtin),
* then exec(2)s `pwd_binary` as a child process. The output of
* pwd_binary goes to stdout.
*
* Exit codes:
* 0 – pwd_binary exited 0
* 1 – setup failure (mkdir/chdir/exec)
* N – whatever pwd_binary exited with
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#define _GNU_SOURCE 1
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
int
main(int argc, char *argv[])
{
long depth;
char *end;
const char *segment;
const char *pwd_bin;
int i, status;
pid_t child;
if (argc != 4) {
fprintf(stderr, "usage: deep_helper <depth> <segment> <pwd_binary>\n");
return 1;
}
errno = 0;
depth = strtol(argv[1], &end, 10);
if (end == argv[1] || *end != '\0' || errno != 0 || depth < 0) {
fprintf(stderr, "deep_helper: invalid depth: %s\n", argv[1]);
return 1;
}
segment = argv[2];
pwd_bin = argv[3];
for (i = 0; i < (int)depth; i++) {
if (mkdir(segment, 0755) != 0 && errno != EEXIST) {
fprintf(stderr, "deep_helper: mkdir(%s) at depth %d: %s\n",
segment, i, strerror(errno));
return 1;
}
if (chdir(segment) != 0) {
/*
* chdir(2) with a single short component should not fail
* ENAMETOOLONG on Linux even when the cumulative path
* exceeds PATH_MAX. If it does, report it clearly.
*/
fprintf(stderr, "deep_helper: chdir(%s) at depth %d: %s\n",
segment, i, strerror(errno));
return 1;
}
}
/* Unset PWD so pwd(1) falls back to getcwd(NULL, 0). */
if (unsetenv("PWD") != 0) {
fprintf(stderr, "deep_helper: unsetenv(PWD): %s\n",
strerror(errno));
return 1;
}
/* Fork so we can capture the exit status of pwd_bin. */
child = fork();
if (child == -1) {
fprintf(stderr, "deep_helper: fork: %s\n", strerror(errno));
return 1;
}
if (child == 0) {
/* Child: exec pwd_bin with no arguments (default -L) */
char *args[] = { (char *)pwd_bin, "-P", NULL };
execv(pwd_bin, args);
fprintf(stderr, "deep_helper: execv(%s): %s\n",
pwd_bin, strerror(errno));
_exit(1);
}
/* Parent: wait for child. */
if (waitpid(child, &status, 0) == -1) {
fprintf(stderr, "deep_helper: waitpid: %s\n", strerror(errno));
return 1;
}
if (WIFEXITED(status))
return WEXITSTATUS(status);
fprintf(stderr, "deep_helper: pwd_bin killed by signal %d\n",
WTERMSIG(status));
return 1;
}
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