[thirdparty/git.git] / pager.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;
}
Commit	Line	Data
	1	#include "cache.h"
	2	#include "run-command.h"
	3	#include "sigchain.h"
	4
	5	#ifndef DEFAULT_PAGER
	6	#define DEFAULT_PAGER "less"
	7	#endif
	8
	9	/*
	10	* This is split up from the rest of git so that we can do
	11	* something different on Windows.
	12	*/
	13
	14	static int spawned_pager;
	15
	16	#ifndef WIN32
	17	static void pager_preexec(void)
	18	{
	19	/*
	20	* Work around bug in "less" by not starting it until we
	21	* have real input
	22	*/
	23	fd_set in;
	24
	25	FD_ZERO(&in);
	26	FD_SET(0, &in);
	27	select(1, &in, NULL, &in, NULL);
	28	}
	29	#endif
	30
	31	static const char *pager_argv[] = { NULL, NULL };
	32	static struct child_process pager_process;
	33
	34	static void wait_for_pager(void)
	35	{
	36	fflush(stdout);
	37	fflush(stderr);
	38	/* signal EOF to pager */
	39	close(1);
	40	close(2);
	41	finish_command(&pager_process);
	42	}
	43
	44	static void wait_for_pager_signal(int signo)
	45	{
	46	wait_for_pager();
	47	sigchain_pop(signo);
	48	raise(signo);
	49	}
	50
	51	const char *git_pager(int stdout_is_tty)
	52	{
	53	const char *pager;
	54
	55	if (!stdout_is_tty)
	56	return NULL;
	57
	58	pager = getenv("GIT_PAGER");
	59	if (!pager) {
	60	if (!pager_program)
	61	git_config(git_default_config, NULL);
	62	pager = pager_program;
	63	}
	64	if (!pager)
	65	pager = getenv("PAGER");
	66	if (!pager)
	67	pager = DEFAULT_PAGER;
	68	else if (!*pager \|\| !strcmp(pager, "cat"))
	69	pager = NULL;
	70
	71	return pager;
	72	}
	73
	74	void setup_pager(void)
	75	{
	76	const char *pager = git_pager(isatty(1));
	77
	78	if (!pager)
	79	return;
	80
	81	spawned_pager = 1; /* means we are emitting to terminal */
	82
	83	/* spawn the pager */
	84	pager_argv[0] = pager;
	85	pager_process.use_shell = 1;
	86	pager_process.argv = pager_argv;
	87	pager_process.in = -1;
	88	if (!getenv("LESS")) {
	89	static const char *env[] = { "LESS=FRSX", NULL };
	90	pager_process.env = env;
	91	}
	92	#ifndef WIN32
	93	pager_process.preexec_cb = pager_preexec;
	94	#endif
	95	if (start_command(&pager_process))
	96	return;
	97
	98	/* original process continues, but writes to the pipe */
	99	dup2(pager_process.in, 1);
	100	if (isatty(2))
	101	dup2(pager_process.in, 2);
	102	close(pager_process.in);
	103
	104	/* this makes sure that the parent terminates after the pager */
	105	sigchain_push_common(wait_for_pager_signal);
	106	atexit(wait_for_pager);
	107	}
	108
	109	int pager_in_use(void)
	110	{
	111	const char *env;
	112
	113	if (spawned_pager)
	114	return 1;
	115
	116	env = getenv("GIT_PAGER_IN_USE");
	117	return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
	118	}