From: Rich Felker <dalias@aerifal.cx>
To: musl@lists.openwall.com
Subject: Re: proposed popen replacement using posix_spawn
Date: Sat, 23 Mar 2013 21:40:57 -0400 [thread overview]
Message-ID: <20130324014057.GX20323@brightrain.aerifal.cx> (raw)
In-Reply-To: <20130324014017.GW20323@brightrain.aerifal.cx>
[-- Attachment #1: Type: text/plain, Size: 266 bytes --]
On Sat, Mar 23, 2013 at 09:40:17PM -0400, Rich Felker wrote:
> Hi all,
>
> I've rewritten popen using posix_spawn and, based on minimal testing,
> it seems to be working. Please take a look and let me know if you see
And here's the forgotten attachment. :-)
Rich
[-- Attachment #2: popen.c --]
[-- Type: text/plain, Size: 1187 bytes --]
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <spawn.h>
#include "stdio_impl.h"
#include "syscall.h"
extern char **__environ;
FILE *popen(const char *cmd, const char *mode)
{
int p[2], op, e;
pid_t pid;
FILE *f;
posix_spawn_file_actions_t fa;
if (*mode == 'r') {
op = 0;
} else if (*mode == 'w') {
op = 1;
} else {
errno = EINVAL;
return 0;
}
if (pipe2(p, O_CLOEXEC)) return NULL;
f = fdopen(p[op], mode);
if (!f) {
__syscall(SYS_close, p[0]);
__syscall(SYS_close, p[1]);
return NULL;
}
FLOCK(f);
/* Remove close-on-exec flag if dup2 will be a no-op in the child */
if (p[1-op] == 1-op) fcntl(1-op, F_SETFD, 0);
e = ENOMEM;
if (!posix_spawn_file_actions_init(&fa)) {
if (!posix_spawn_file_actions_adddup2(&fa, p[1-op], 1-op)) {
if (!(e = posix_spawn(&pid, "/bin/sh", &fa, 0,
(char *[]){ "sh", "-c", (char *)cmd, 0 }, __environ))) {
posix_spawn_file_actions_destroy(&fa);
f->pipe_pid = pid;
fcntl(p[op], F_SETFD, 0);
__syscall(SYS_close, p[1-op]);
FUNLOCK(f);
return f;
}
}
posix_spawn_file_actions_destroy(&fa);
}
fclose(f);
__syscall(SYS_close, p[1-op]);
errno = e;
return 0;
}
next prev parent reply other threads:[~2013-03-24 1:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-24 1:40 Rich Felker
2013-03-24 1:40 ` Rich Felker [this message]
2013-03-24 1:45 ` Rich Felker
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20130324014057.GX20323@brightrain.aerifal.cx \
--to=dalias@aerifal.cx \
--cc=musl@lists.openwall.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.vuxu.org/mirror/musl/
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).