git/pager.c
Junio C Hamano 342c14db8c Merge branch 'jc/unexport-git-pager-in-use-in-pager' into maint
When you say "!<ENTER>" while running say "git log", you'd confuse
yourself in the resulting shell, that may look as if you took
control back to the original shell you spawned "git log" from but
that isn't what is happening.  To that new shell, we leaked
GIT_PAGER_IN_USE environment variable that was meant as a local
communication between the original "Git" and subprocesses that was
spawned by it after we launched the pager, which caused many
"interesting" things to happen, e.g. "git diff | cat" still paints
its output in color by default.

Stop leaking that environment variable to the pager's half of the
fork; we only need it on "Git" side when we spawn the pager.

* jc/unexport-git-pager-in-use-in-pager:
  pager: do not leak "GIT_PAGER_IN_USE" to the pager
2015-07-27 12:21:44 -07:00

165 lines
3.4 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 const char *pager_argv[] = { NULL, NULL };
static struct child_process pager_process = CHILD_PROCESS_INIT;
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;
if (!*pager || !strcmp(pager, "cat"))
pager = NULL;
return pager;
}
void setup_pager(void)
{
const char *pager = git_pager(isatty(1));
if (!pager)
return;
/*
* force computing the width of the terminal before we redirect
* the standard output to the pager.
*/
(void) term_columns();
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"))
argv_array_push(&pager_process.env_array, "LESS=FRX");
if (!getenv("LV"))
argv_array_push(&pager_process.env_array, "LV=-c");
argv_array_push(&pager_process.env_array, "GIT_PAGER_IN_USE");
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;
}
/*
* Return cached value (if set) or $COLUMNS environment variable (if
* set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
* and default to 80 if all else fails.
*/
int term_columns(void)
{
static int term_columns_at_startup;
char *col_string;
int n_cols;
if (term_columns_at_startup)
return term_columns_at_startup;
term_columns_at_startup = 80;
col_string = getenv("COLUMNS");
if (col_string && (n_cols = atoi(col_string)) > 0)
term_columns_at_startup = n_cols;
#ifdef TIOCGWINSZ
else {
struct winsize ws;
if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
term_columns_at_startup = ws.ws_col;
}
#endif
return term_columns_at_startup;
}
/*
* How many columns do we need to show this number in decimal?
*/
int decimal_width(uintmax_t number)
{
int width;
for (width = 1; number >= 10; width++)
number /= 10;
return width;
}
/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
int check_pager_config(const char *cmd)
{
int want = -1;
struct strbuf key = STRBUF_INIT;
const char *value = NULL;
strbuf_addf(&key, "pager.%s", cmd);
if (!git_config_get_value(key.buf, &value)) {
int b = git_config_maybe_bool(key.buf, value);
if (b >= 0)
want = b;
else {
want = 1;
pager_program = xstrdup(value);
}
}
strbuf_release(&key);
return want;
}