Audit nohup(1)

1) no need to include sys/stat.h
2) remove the enum which just added a layer too thick on this simple
   program
3) argc-style, other style
4) weprintf instead of enprintf, then save the error-message of
   execvp before and return the proper status.
5) write consistent "not reached" comment.
This commit is contained in:
FRIGN 2015-03-04 22:39:12 +01:00
parent 4c4e5a3eb2
commit a6ee96af7c
2 changed files with 15 additions and 21 deletions

2
README
View File

@ -50,7 +50,7 @@ The following tools are implemented ('*' == finished, '#' == UTF-8 support,
=* mv yes none (-i)
=*| nice yes none
= nl no -d, -f, -h, -l, -p
=* nohup yes none
=*| nohup yes none
#* paste yes none
=*| printenv non-posix none
#* printf yes none

34
nohup.c
View File

@ -1,6 +1,4 @@
/* See LICENSE file for copyright and license details. */
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
@ -8,8 +6,6 @@
#include "util.h"
enum { Error = 127, Found = 126 };
static void
usage(void)
{
@ -19,35 +15,33 @@ usage(void)
int
main(int argc, char *argv[])
{
int fd;
int fd, savederrno;
ARGBEGIN {
default:
usage();
} ARGEND;
if (argc == 0)
if (!argc)
usage();
if (signal(SIGHUP, SIG_IGN) == SIG_ERR)
enprintf(Error, "signal HUP:");
enprintf(127, "signal HUP:");
if (isatty(STDOUT_FILENO)) {
if ((fd = open("nohup.out", O_APPEND|O_CREAT,
S_IRUSR|S_IWUSR)) < 0) {
enprintf(Error, "open nohup.out:");
}
if ((fd = open("nohup.out", O_APPEND | O_CREAT, S_IRUSR | S_IWUSR)) < 0)
enprintf(127, "open nohup.out:");
if (dup2(fd, STDOUT_FILENO) < 0)
enprintf(Error, "dup2:");
enprintf(127, "dup2:");
close(fd);
}
if (isatty(STDERR_FILENO))
if (dup2(STDOUT_FILENO, STDERR_FILENO) < 0)
enprintf(Error, "dup2:");
if (isatty(STDERR_FILENO) && dup2(STDOUT_FILENO, STDERR_FILENO) < 0)
enprintf(127, "dup2:");
execvp(argv[0], &argv[0]);
enprintf(errno == ENOENT ? Error : Found, "exec %s:", argv[0]);
_exit(Error);
/* unreachable */
return 0;
execvp(argv[0], argv);
savederrno = errno;
weprintf("exec %s:", argv[0]);
_exit(126 + (savederrno == ENOENT));
return 0; /* not reached */
}