Commands executing another command (e.g. taskset) should fail in a
consistent and detectable way when the other command fail to execute.
Change most of the commands that used to fail with EXIT_FAILURE to fail
with the special exit code 127, like the shell.
For example, running the fuser command via taskset when fuser command is
not installed is failing now like this:
$ taskset -c 1 fuser /path/to/file; echo $?
taskset: failed to execute fuser: No such file or directory
1
This failure looks like a real failure of the fuser command:
$ taskset -c 1 fuser /path/to/file; echo $?
Specified filename /path/to/file does not exist.
1
Based on the exit code, a management program may do the wrong thing,
leading to catastrophic results. Detecting such failure requires fragile
parsing of standard error.
With this patch this failure is easy to detect:
$ taskset -c 1 fuser /path/to/file; echo $?
taskset: failed to execute fuser: No such file or directory
127
The return code seems to be undocumented for most commands, except the
su command, promising to exit with exit code 126 if a command cannot be
executed, and 127 if a command was not found. However, the actual
command always exit with exit code 1. This patch implement the
documented behavior.
Signed-off-by: Nir Soffer <nsoffer@xxxxxxxxxx>
---
disk-utils/mkfs.c | 3 ++-
include/exitcodes.h | 7 +++++++
lib/pager.c | 3 ++-
login-utils/su-common.c | 7 ++++++-
schedutils/chrt.c | 3 ++-
schedutils/ionice.c | 3 ++-
schedutils/taskset.c | 3 ++-
sys-utils/flock.c | 4 +++-
sys-utils/nsenter.c | 3 ++-
sys-utils/prlimit.c | 3 ++-
sys-utils/setarch.c | 7 ++++---
sys-utils/setpriv.c | 3 ++-
sys-utils/setsid.c | 3 ++-
sys-utils/swapon.c | 3 ++-
sys-utils/unshare.c | 3 ++-
tests/expected/misc/setarch-options | 2 +-
text-utils/more.c | 3 ++-
17 files changed, 45 insertions(+), 18 deletions(-)
diff --git a/disk-utils/mkfs.c b/disk-utils/mkfs.c
index cf1a312..88f125d 100644
--- a/disk-utils/mkfs.c
+++ b/disk-utils/mkfs.c
@@ -33,6 +33,7 @@
#include "closestream.h"
#include "nls.h"
#include "xalloc.h"
+#include "exitcodes.h"
#ifndef DEFAULT_FSTYPE
#define DEFAULT_FSTYPE "ext2"
@@ -136,5 +137,5 @@ int main(int argc, char **argv)
/* Execute the program */
execvp(progname, argv + optind);
- err(EXIT_FAILURE, _("failed to execute %s"), progname);
+ err(EX_EXEC, _("failed to execute %s"), progname);
}
diff --git a/include/exitcodes.h b/include/exitcodes.h
index 24ee123..2063c54 100644
--- a/include/exitcodes.h
+++ b/include/exitcodes.h
@@ -32,4 +32,11 @@
#define MOUNT_EX_FAIL 32 /* mount failure */
#define MOUNT_EX_SOMEOK 64 /* some mount succeeded */
+/* Exit codes use by the su program */
+#define SU_EX_EXEC 126 /* faied to execute a program */
+#define SU_EX_NOENT 127 /* program was not found */
+
+/* General exit codes */
+#define EX_EXEC 127 /* faied to execute a program */
+
#endif /* UTIL_LINUX_EXITCODES_H */
diff --git a/lib/pager.c b/lib/pager.c
index 330659e..381294a 100644
--- a/lib/pager.c
+++ b/lib/pager.c
@@ -17,6 +17,7 @@
#include "c.h"
#include "xalloc.h"
#include "nls.h"
+#include "exitcodes.h"
#define NULL_DEVICE "/dev/null"
@@ -73,7 +74,7 @@ static int start_command(struct child_process *cmd)
cmd->preexec_cb();
execvp(cmd->argv[0], (char *const*) cmd->argv);
- exit(127); /* cmd not found */
+ exit(EX_EXEC); /* cmd not found */
}
if (cmd->pid < 0) {
diff --git a/login-utils/su-common.c b/login-utils/su-common.c
index fe6d0c8..b17b133 100644
--- a/login-utils/su-common.c
+++ b/login-utils/su-common.c
@@ -71,6 +71,7 @@ enum
#include "closestream.h"
#include "strutils.h"
#include "ttyutils.h"
+#include "exitcodes.h"
/* name of the pam configuration files. separate configs for su and su - */
#define PAM_SRVNAME_SU "su"
@@ -983,7 +984,11 @@ su_main (int argc, char **argv, int mode)
run_shell (shell, command, argv + optind, max (0, argc - optind));
else {
execvp(argv[optind], &argv[optind]);
- err(EXIT_FAILURE, _("failed to execute %s"), argv[optind]);
+ /* su(1) promise to fail with exit code 126 if the command
+ cannot be executed, and 127 if the command was not
+ found. */
+ err(errno == ENOENT ? SU_EX_NOENT : SU_EX_EXEC,
+ _("failed to execute %s"), argv[optind]);
}
}
diff --git a/schedutils/chrt.c b/schedutils/chrt.c
index 202ce25..40f6cfe 100644
--- a/schedutils/chrt.c
+++ b/schedutils/chrt.c
@@ -32,6 +32,7 @@
#include "closestream.h"
#include "strutils.h"
#include "procutils.h"
+#include "exitcodes.h"
/* the SCHED_BATCH is supported since Linux 2.6.16
* -- temporary workaround for people with old glibc headers
@@ -517,7 +518,7 @@ int main(int argc, char **argv)
if (!ctl->pid) {
argv += optind + 1;
execvp(argv[0], argv);
- err(EXIT_FAILURE, _("failed to execute %s"), argv[0]);
+ err(EX_EXEC, _("failed to execute %s"), argv[0]);
}
return EXIT_SUCCESS;
diff --git a/schedutils/ionice.c b/schedutils/ionice.c
index 5528afe..0d6a2d2 100644
--- a/schedutils/ionice.c
+++ b/schedutils/ionice.c
@@ -18,6 +18,7 @@
#include "strutils.h"
#include "c.h"
#include "closestream.h"
+#include "exitcodes.h"
static int tolerant;
@@ -257,7 +258,7 @@ int main(int argc, char **argv)
*/
ioprio_setid(0, ioclass, data, IOPRIO_WHO_PROCESS);
execvp(argv[optind], &argv[optind]);
- err(EXIT_FAILURE, _("failed to execute %s"), argv[optind]);
+ err(EX_EXEC, _("failed to execute %s"), argv[optind]);
} else
usage(stderr);
diff --git a/schedutils/taskset.c b/schedutils/taskset.c
index d6b21e4..e68068d 100644
--- a/schedutils/taskset.c
+++ b/schedutils/taskset.c
@@ -34,6 +34,7 @@
#include "procutils.h"
#include "c.h"
#include "closestream.h"
+#include "exitcodes.h"
struct taskset {
pid_t pid; /* task PID */
@@ -236,7 +237,7 @@ int main(int argc, char **argv)
if (!pid) {
argv += optind + 1;
execvp(argv[0], argv);
- err(EXIT_FAILURE, _("failed to execute %s"), argv[0]);
+ err(EX_EXEC, _("failed to execute %s"), argv[0]);
}
return EXIT_SUCCESS;
diff --git a/sys-utils/flock.c b/sys-utils/flock.c
index b5c4d91..d2d994a 100644
--- a/sys-utils/flock.c
+++ b/sys-utils/flock.c
@@ -45,6 +45,7 @@
#include "closestream.h"
#include "monotonic.h"
#include "timer.h"
+#include "exitcodes.h"
static void __attribute__((__noreturn__)) usage(int ex)
{
@@ -330,7 +331,8 @@ int main(int argc, char *argv[])
execvp(cmd_argv[0], cmd_argv);
/* execvp() failed */
warn(_("failed to execute %s"), cmd_argv[0]);
- _exit((errno == ENOMEM) ? EX_OSERR : EX_UNAVAILABLE);
+ /* Behave mostly like the shell */
+ _exit((errno == ENOMEM) ? EX_OSERR : EX_EXEC);
} else {
do {
w = waitpid(f, &status, 0);
diff --git a/sys-utils/nsenter.c b/sys-utils/nsenter.c
index d8690db..558b4d0 100644
--- a/sys-utils/nsenter.c
+++ b/sys-utils/nsenter.c
@@ -40,6 +40,7 @@
#include "closestream.h"
#include "namespace.h"
#include "exec_shell.h"
+#include "exitcodes.h"
static struct namespace_file {
int nstype;
@@ -413,7 +414,7 @@ int main(int argc, char *argv[])
if (optind < argc) {
execvp(argv[optind], argv + optind);
- err(EXIT_FAILURE, _("failed to execute %s"), argv[optind]);
+ err(EX_EXEC, _("failed to execute %s"), argv[optind]);
}
exec_shell();
}
diff --git a/sys-utils/prlimit.c b/sys-utils/prlimit.c
index b244ddb..6a3d527 100644
--- a/sys-utils/prlimit.c
+++ b/sys-utils/prlimit.c
@@ -35,6 +35,7 @@
#include "strutils.h"
#include "list.h"
#include "closestream.h"
+#include "exitcodes.h"
#ifndef RLIMIT_RTTIME
# define RLIMIT_RTTIME 15
@@ -641,7 +642,7 @@ int main(int argc, char **argv)
if (argc > optind) {
/* prlimit [options] COMMAND */
execvp(argv[optind], &argv[optind]);
- err(EXIT_FAILURE, _("failed to execute %s"), argv[optind]);
+ err(EX_EXEC, _("failed to execute %s"), argv[optind]);
}
return EXIT_SUCCESS;
diff --git a/sys-utils/setarch.c b/sys-utils/setarch.c
index cf29cf7..bda3e8f 100644
--- a/sys-utils/setarch.c
+++ b/sys-utils/setarch.c
@@ -35,6 +35,7 @@
#include "nls.h"
#include "c.h"
#include "closestream.h"
+#include "exitcodes.h"
#ifndef HAVE_PERSONALITY
# include <syscall.h>
@@ -399,10 +400,10 @@ int main(int argc, char *argv[])
if (!argc) {
execl("/bin/sh", "-sh", NULL);
- err(EXIT_FAILURE, _("failed to execute %s"), "/bin/sh");
+ err(EX_EXEC, _("failed to execute %s"), "/bin/sh");
}
execvp(argv[0], argv);
- err(EXIT_FAILURE, "%s", argv[0]);
- return EXIT_FAILURE;
+ err(EX_EXEC, "%s", argv[0]);
+ return EX_EXEC;
}
diff --git a/sys-utils/setpriv.c b/sys-utils/setpriv.c
index 1630122..2015f30 100644
--- a/sys-utils/setpriv.c
+++ b/sys-utils/setpriv.c
@@ -38,6 +38,7 @@
#include "strutils.h"
#include "xalloc.h"
#include "pathnames.h"
+#include "exitcodes.h"
#ifndef PR_SET_NO_NEW_PRIVS
# define PR_SET_NO_NEW_PRIVS 38
@@ -839,5 +840,5 @@ int main(int argc, char **argv)
execvp(argv[optind], argv + optind);
- err(EXIT_FAILURE, _("cannot execute: %s"), argv[optind]);
+ err(EX_EXEC, _("cannot execute: %s"), argv[optind]);
}
diff --git a/sys-utils/setsid.c b/sys-utils/setsid.c
index bb089df..466c5cf 100644
--- a/sys-utils/setsid.c
+++ b/sys-utils/setsid.c
@@ -24,6 +24,7 @@
#include "c.h"
#include "nls.h"
#include "closestream.h"
+#include "exitcodes.h"
static void __attribute__ ((__noreturn__)) usage(FILE * out)
{
@@ -114,5 +115,5 @@ int main(int argc, char **argv)
err(EXIT_FAILURE, _("failed to set the controlling terminal"));
}
execvp(argv[optind], argv + optind);
- err(EXIT_FAILURE, _("failed to execute %s"), argv[optind]);
+ err(EX_EXEC, _("failed to execute %s"), argv[optind]);
}
diff --git a/sys-utils/swapon.c b/sys-utils/swapon.c
index 97acf1e..294112b 100644
--- a/sys-utils/swapon.c
+++ b/sys-utils/swapon.c
@@ -23,6 +23,7 @@
#include "strutils.h"
#include "optutils.h"
#include "closestream.h"
+#include "exitcodes.h"
#include "swapheader.h"
#include "swapprober.h"
@@ -337,7 +338,7 @@ static int swap_reinitialize(struct swap_device *dev)
cmd[idx++] = dev->path;
cmd[idx++] = NULL;
execvp(cmd[0], (char * const *) cmd);
- err(EXIT_FAILURE, _("failed to execute %s"), cmd[0]);
+ err(EX_EXEC, _("failed to execute %s"), cmd[0]);
default: /* parent */
do {
diff --git a/sys-utils/unshare.c b/sys-utils/unshare.c
index 234c750..9e6b4bb 100644
--- a/sys-utils/unshare.c
+++ b/sys-utils/unshare.c
@@ -40,6 +40,7 @@
#include "xalloc.h"
#include "pathnames.h"
#include "all-io.h"
+#include "exitcodes.h"
/* synchronize parent and child by pipe */
#define PIPE_SYNC_BYTE 0x06
@@ -458,7 +459,7 @@ int main(int argc, char *argv[])
if (optind < argc) {
execvp(argv[optind], argv + optind);
- err(EXIT_FAILURE, _("failed to execute %s"), argv[optind]);
+ err(EX_EXEC, _("failed to execute %s"), argv[optind]);
}
exec_shell();
}
diff --git a/tests/expected/misc/setarch-options b/tests/expected/misc/setarch-options
index 698db52..ebe52f0 100644
--- a/tests/expected/misc/setarch-options
+++ b/tests/expected/misc/setarch-options
@@ -4,7 +4,7 @@ exit: 1
###### unknown command
Execute command `/das/gibs/nicht'.
setarch: /das/gibs/nicht: No such file or directory
-exit: 1
+exit: 127
###### noop uname -a
Execute command `uname'.
uname -a unchanged
diff --git a/text-utils/more.c b/text-utils/more.c
index 0a5f494..42f49ba 100644
--- a/text-utils/more.c
+++ b/text-utils/more.c
@@ -65,6 +65,7 @@
#include "xalloc.h"
#include "widechar.h"
#include "closestream.h"
+#include "exitcodes.h"
#include <regex.h>
@@ -1622,7 +1623,7 @@ void execute(char *filename, char *cmd, ...)
execvp(cmd, args);
putserr(_("exec failed\n"));
- exit(EXIT_FAILURE);
+ exit(EX_EXEC);
}
if (id > 0) {
signal(SIGINT, SIG_IGN);
--
2.4.11
--
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