git/pager.c
Junio C Hamano a8335024c2 pager: do not dup2 stderr if it is already redirected
An earlier commit 61b8050 (sending errors to stdout under $PAGER,
2008-02-16) avoided losing the error messages that are sent to the
standard error when $PAGER is in effect by dup2'ing fd 2 to the pager.
his way, showing a tag object that points to a bad object:

    $ git show tag-foo

would give the error message to the pager.  However, it was not quite
right if the user did:

    $ git show 2>error.log tag-foo

i.e. use the pager but store the errors in a separate file.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-12-15 01:37:15 -08:00

123 lines
2.2 KiB
C

#include "cache.h"
/*
* This is split up from the rest of git so that we can do
* something different on Windows.
*/
static int spawned_pager;
#ifndef __MINGW32__
static void run_pager(const char *pager)
{
/*
* Work around bug in "less" by not starting it until we
* have real input
*/
fd_set in;
FD_ZERO(&in);
FD_SET(0, &in);
select(1, &in, NULL, &in, NULL);
execlp(pager, pager, NULL);
execl("/bin/sh", "sh", "-c", pager, NULL);
}
#else
#include "run-command.h"
static const char *pager_argv[] = { "sh", "-c", NULL, NULL };
static struct child_process pager_process = {
.argv = pager_argv,
.in = -1
};
static void wait_for_pager(void)
{
fflush(stdout);
fflush(stderr);
/* signal EOF to pager */
close(1);
close(2);
finish_command(&pager_process);
}
#endif
void setup_pager(void)
{
#ifndef __MINGW32__
pid_t pid;
int fd[2];
#endif
const char *pager = getenv("GIT_PAGER");
if (!isatty(1))
return;
if (!pager) {
if (!pager_program)
git_config(git_default_config, NULL);
pager = pager_program;
}
if (!pager)
pager = getenv("PAGER");
if (!pager)
pager = "less";
else if (!*pager || !strcmp(pager, "cat"))
return;
spawned_pager = 1; /* means we are emitting to terminal */
#ifndef __MINGW32__
if (pipe(fd) < 0)
return;
pid = fork();
if (pid < 0) {
close(fd[0]);
close(fd[1]);
return;
}
/* return in the child */
if (!pid) {
dup2(fd[1], 1);
dup2(fd[1], 2);
close(fd[0]);
close(fd[1]);
return;
}
/* The original process turns into the PAGER */
dup2(fd[0], 0);
close(fd[0]);
close(fd[1]);
setenv("LESS", "FRSX", 0);
run_pager(pager);
die("unable to execute pager '%s'", pager);
exit(255);
#else
/* spawn the pager */
pager_argv[2] = pager;
if (start_command(&pager_process))
return;
/* original process continues, but writes to the pipe */
dup2(pager_process.in, 1);
if (isatty(2))
dup2(pager_process.in, 2);
close(pager_process.in);
/* this makes sure that the parent terminates after the pager */
atexit(wait_for_pager);
#endif
}
int pager_in_use(void)
{
const char *env;
if (spawned_pager)
return 1;
env = getenv("GIT_PAGER_IN_USE");
return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
}