git/pager.c
Jonathan Nieder 64778d24a9 Make 'git var GIT_PAGER' always print the configured pager
Scripted commands that want to use git’s configured pager know better
than ‘git var’ does whether stdout is going to be a tty at the
appropriate time.  Checking isatty(1) as git_pager() does now won’t
cut it, since the output of git var itself is almost never a terminal.
The symptom is that when used by humans, ‘git var GIT_PAGER’ behaves
as it should, but when used by scripts, it always returns ‘cat’!

So avoid tricks with isatty() and just always print the configured
pager.

This does not fix the callers to check isatty(1) themselves yet.
Nevertheless, this patch alone is enough to fix 'am --interactive'.

Thanks to Sebastian Celis for the report and Jeff King for the
analysis.

Reported-by: Sebastian Celis <sebastian@sebastiancelis.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-14 18:23:17 -08:00

119 lines
2.2 KiB
C

#include "cache.h"
#include "run-command.h"
#include "sigchain.h"
#ifndef DEFAULT_PAGER
#define DEFAULT_PAGER "less"
#endif
/*
* This is split up from the rest of git so that we can do
* something different on Windows.
*/
static int spawned_pager;
#ifndef WIN32
static void pager_preexec(void)
{
/*
* 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);
}
#endif
static const char *pager_argv[] = { NULL, NULL };
static struct child_process pager_process;
static void wait_for_pager(void)
{
fflush(stdout);
fflush(stderr);
/* signal EOF to pager */
close(1);
close(2);
finish_command(&pager_process);
}
static void wait_for_pager_signal(int signo)
{
wait_for_pager();
sigchain_pop(signo);
raise(signo);
}
const char *git_pager(int stdout_is_tty)
{
const char *pager;
if (!stdout_is_tty)
return NULL;
pager = getenv("GIT_PAGER");
if (!pager) {
if (!pager_program)
git_config(git_default_config, NULL);
pager = pager_program;
}
if (!pager)
pager = getenv("PAGER");
if (!pager)
pager = DEFAULT_PAGER;
else if (!*pager || !strcmp(pager, "cat"))
pager = NULL;
return pager;
}
void setup_pager(void)
{
const char *pager = git_pager(isatty(1));
if (!pager)
return;
spawned_pager = 1; /* means we are emitting to terminal */
/* spawn the pager */
pager_argv[0] = pager;
pager_process.use_shell = 1;
pager_process.argv = pager_argv;
pager_process.in = -1;
if (!getenv("LESS")) {
static const char *env[] = { "LESS=FRSX", NULL };
pager_process.env = env;
}
#ifndef WIN32
pager_process.preexec_cb = pager_preexec;
#endif
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 */
sigchain_push_common(wait_for_pager_signal);
atexit(wait_for_pager);
}
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;
}