git.uis.cam.ac.uk - uis - git/git.git/blame_incremental

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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	static struct child_process pager_process = CHILD_PROCESS_INIT;
	10
	11	static void wait_for_pager(int in_signal)
	12	{
	13	if (!in_signal) {
	14	fflush(stdout);
	15	fflush(stderr);
	16	}
	17	/* signal EOF to pager */
	18	close(1);
	19	close(2);
	20	if (in_signal)
	21	finish_command_in_signal(&pager_process);
	22	else
	23	finish_command(&pager_process);
	24	}
	25
	26	static void wait_for_pager_atexit(void)
	27	{
	28	wait_for_pager(0);
	29	}
	30
	31	static void wait_for_pager_signal(int signo)
	32	{
	33	wait_for_pager(1);
	34	sigchain_pop(signo);
	35	raise(signo);
	36	}
	37
	38	const char *git_pager(int stdout_is_tty)
	39	{
	40	const char *pager;
	41
	42	if (!stdout_is_tty)
	43	return NULL;
	44
	45	pager = getenv("GIT_PAGER");
	46	if (!pager) {
	47	if (!pager_program)
	48	git_config(git_default_config, NULL);
	49	pager = pager_program;
	50	}
	51	if (!pager)
	52	pager = getenv("PAGER");
	53	if (!pager)
	54	pager = DEFAULT_PAGER;
	55	if (!*pager \|\| !strcmp(pager, "cat"))
	56	pager = NULL;
	57
	58	return pager;
	59	}
	60
	61	void prepare_pager_args(struct child_process pager_process, const char pager)
	62	{
	63	argv_array_push(&pager_process->args, pager);
	64	pager_process->use_shell = 1;
	65	if (!getenv("LESS"))
	66	argv_array_push(&pager_process->env_array, "LESS=FRX");
	67	if (!getenv("LV"))
	68	argv_array_push(&pager_process->env_array, "LV=-c");
	69	}
	70
	71	void setup_pager(void)
	72	{
	73	const char *pager = git_pager(isatty(1));
	74
	75	if (!pager)
	76	return;
	77
	78	/*
	79	* force computing the width of the terminal before we redirect
	80	* the standard output to the pager.
	81	*/
	82	(void) term_columns();
	83
	84	setenv("GIT_PAGER_IN_USE", "true", 1);
	85
	86	/* spawn the pager */
	87	prepare_pager_args(&pager_process, pager);
	88	pager_process.in = -1;
	89	argv_array_push(&pager_process.env_array, "GIT_PAGER_IN_USE");
	90	if (start_command(&pager_process))
	91	return;
	92
	93	/* original process continues, but writes to the pipe */
	94	dup2(pager_process.in, 1);
	95	if (isatty(2))
	96	dup2(pager_process.in, 2);
	97	close(pager_process.in);
	98
	99	/* this makes sure that the parent terminates after the pager */
	100	sigchain_push_common(wait_for_pager_signal);
	101	atexit(wait_for_pager_atexit);
	102	}
	103
	104	int pager_in_use(void)
	105	{
	106	const char *env;
	107	env = getenv("GIT_PAGER_IN_USE");
	108	return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
	109	}
	110
	111	/*
	112	* Return cached value (if set) or $COLUMNS environment variable (if
	113	* set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
	114	* and default to 80 if all else fails.
	115	*/
	116	int term_columns(void)
	117	{
	118	static int term_columns_at_startup;
	119
	120	char *col_string;
	121	int n_cols;
	122
	123	if (term_columns_at_startup)
	124	return term_columns_at_startup;
	125
	126	term_columns_at_startup = 80;
	127
	128	col_string = getenv("COLUMNS");
	129	if (col_string && (n_cols = atoi(col_string)) > 0)
	130	term_columns_at_startup = n_cols;
	131	#ifdef TIOCGWINSZ
	132	else {
	133	struct winsize ws;
	134	if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
	135	term_columns_at_startup = ws.ws_col;
	136	}
	137	#endif
	138
	139	return term_columns_at_startup;
	140	}
	141
	142	/*
	143	* How many columns do we need to show this number in decimal?
	144	*/
	145	int decimal_width(uintmax_t number)
	146	{
	147	int width;
	148
	149	for (width = 1; number >= 10; width++)
	150	number /= 10;
	151	return width;
	152	}
	153
	154	/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
	155	int check_pager_config(const char *cmd)
	156	{
	157	int want = -1;
	158	struct strbuf key = STRBUF_INIT;
	159	const char *value = NULL;
	160	strbuf_addf(&key, "pager.%s", cmd);
	161	if (git_config_key_is_valid(key.buf) &&
	162	!git_config_get_value(key.buf, &value)) {
	163	int b = git_config_maybe_bool(key.buf, value);
	164	if (b >= 0)
	165	want = b;
	166	else {
	167	want = 1;
	168	pager_program = xstrdup(value);
	169	}
	170	}
	171	strbuf_release(&key);
	172	return want;
	173	}