git/pager.c
Zbigniew Jędrzejewski-Szmek ec7ff5ba27 make lineno_width() from blame reusable for others
builtin/blame.c has a helper function to compute how many columns
we need to show a line-number, whose implementation is reusable as
a more generic helper function to count the number of columns
necessary to show any cardinal number.

Rename it to decimal_width(), move it to pager.c and export it for
use by future callers.

Signed-off-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-02-14 16:16:19 -08:00

125 lines
2.3 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.
*/
#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;
setenv("GIT_PAGER_IN_USE", "true", 1);
/* 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;
env = getenv("GIT_PAGER_IN_USE");
return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
}
/*
* How many columns do we need to show this number in decimal?
*/
int decimal_width(int number)
{
int i, width;
for (width = 1, i = 10; i <= number; width++)
i *= 10;
return width;
}