pager: remove obsolete comment
[git/git.git] / pager.c
CommitLineData
f67b45f8 1#include "cache.h"
ea27a18c 2#include "run-command.h"
a3da8821 3#include "sigchain.h"
f67b45f8 4
a3d023d0
JH
5#ifndef DEFAULT_PAGER
6#define DEFAULT_PAGER "less"
7#endif
8
d3180279 9static struct child_process pager_process = CHILD_PROCESS_INIT;
ea27a18c 10
507d7804 11static void wait_for_pager(int in_signal)
bfdd9ffd 12{
507d7804
TI
13 if (!in_signal) {
14 fflush(stdout);
15 fflush(stderr);
16 }
bfdd9ffd
JS
17 /* signal EOF to pager */
18 close(1);
19 close(2);
507d7804
TI
20 if (in_signal)
21 finish_command_in_signal(&pager_process);
22 else
23 finish_command(&pager_process);
24}
25
26static void wait_for_pager_atexit(void)
27{
28 wait_for_pager(0);
bfdd9ffd 29}
f67b45f8 30
a3da8821
JK
31static void wait_for_pager_signal(int signo)
32{
507d7804 33 wait_for_pager(1);
a3da8821
JK
34 sigchain_pop(signo);
35 raise(signo);
36}
37
64778d24 38const char *git_pager(int stdout_is_tty)
f67b45f8 39{
63618245 40 const char *pager;
f67b45f8 41
64778d24 42 if (!stdout_is_tty)
63618245
JN
43 return NULL;
44
45 pager = getenv("GIT_PAGER");
cad3a205
JH
46 if (!pager) {
47 if (!pager_program)
ef90d6d4 48 git_config(git_default_config, NULL);
54adf370 49 pager = pager_program;
cad3a205 50 }
c27d205a
ML
51 if (!pager)
52 pager = getenv("PAGER");
402461aa 53 if (!pager)
a3d023d0 54 pager = DEFAULT_PAGER;
ed016612 55 if (!*pager || !strcmp(pager, "cat"))
63618245
JN
56 pager = NULL;
57
58 return pager;
59}
60
3e3a4a41
JH
61void 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
63618245
JN
71void setup_pager(void)
72{
64778d24 73 const char *pager = git_pager(isatty(1));
63618245 74
c0459ca4 75 if (!pager)
402461aa
JS
76 return;
77
ad6c3739
ZJS
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
2e6c012e 84 setenv("GIT_PAGER_IN_USE", "true", 1);
85fb65ed 85
bfdd9ffd 86 /* spawn the pager */
3e3a4a41 87 prepare_pager_args(&pager_process, pager);
ea27a18c 88 pager_process.in = -1;
124b5190 89 argv_array_push(&pager_process.env_array, "GIT_PAGER_IN_USE");
bfdd9ffd
JS
90 if (start_command(&pager_process))
91 return;
92
93 /* original process continues, but writes to the pipe */
94 dup2(pager_process.in, 1);
a8335024
JH
95 if (isatty(2))
96 dup2(pager_process.in, 2);
bfdd9ffd
JS
97 close(pager_process.in);
98
99 /* this makes sure that the parent terminates after the pager */
a3da8821 100 sigchain_push_common(wait_for_pager_signal);
507d7804 101 atexit(wait_for_pager_atexit);
f67b45f8 102}
6e9af863
JK
103
104int pager_in_use(void)
105{
106 const char *env;
6e9af863
JK
107 env = getenv("GIT_PAGER_IN_USE");
108 return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
109}
ad6c3739
ZJS
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 */
116int 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}
4d9e079e 141
ec7ff5ba
ZJS
142/*
143 * How many columns do we need to show this number in decimal?
144 */
d306f3d3 145int decimal_width(uintmax_t number)
ec7ff5ba 146{
d306f3d3 147 int width;
ec7ff5ba 148
d306f3d3
JK
149 for (width = 1; number >= 10; width++)
150 number /= 10;
ec7ff5ba
ZJS
151 return width;
152}
4914c962 153
586f414a
TA
154/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
155int check_pager_config(const char *cmd)
4914c962 156{
586f414a
TA
157 int want = -1;
158 struct strbuf key = STRBUF_INIT;
159 const char *value = NULL;
160 strbuf_addf(&key, "pager.%s", cmd);
9e9de18f
JK
161 if (git_config_key_is_valid(key.buf) &&
162 !git_config_get_value(key.buf, &value)) {
586f414a 163 int b = git_config_maybe_bool(key.buf, value);
4914c962 164 if (b >= 0)
586f414a 165 want = b;
4914c962 166 else {
586f414a
TA
167 want = 1;
168 pager_program = xstrdup(value);
4914c962
NTND
169 }
170 }
586f414a
TA
171 strbuf_release(&key);
172 return want;
4914c962 173}