fc210f951d50add067dcb8f13d231e3b72148c25
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
9static struct child_process pager_process = CHILD_PROCESS_INIT;
10
11static 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
26static void wait_for_pager_atexit(void)
27{
28 wait_for_pager(0);
29}
30
31static void wait_for_pager_signal(int signo)
32{
33 wait_for_pager(1);
34 sigchain_pop(signo);
35 raise(signo);
36}
37
38static int core_pager_config(const char *var, const char *value, void *data)
39{
40 if (!strcmp(var, "core.pager"))
41 return git_config_string(&pager_program, var, value);
42 return 0;
43}
44
45const char *git_pager(int stdout_is_tty)
46{
47 const char *pager;
48
49 if (!stdout_is_tty)
50 return NULL;
51
52 pager = getenv("GIT_PAGER");
53 if (!pager) {
54 if (!pager_program)
55 git_config(core_pager_config, NULL);
56 pager = pager_program;
57 }
58 if (!pager)
59 pager = getenv("PAGER");
60 if (!pager)
61 pager = DEFAULT_PAGER;
62 if (!*pager || !strcmp(pager, "cat"))
63 pager = NULL;
64
65 return pager;
66}
67
68void prepare_pager_args(struct child_process *pager_process, const char *pager)
69{
70 argv_array_push(&pager_process->args, pager);
71 pager_process->use_shell = 1;
72 if (!getenv("LESS"))
73 argv_array_push(&pager_process->env_array, "LESS=FRX");
74 if (!getenv("LV"))
75 argv_array_push(&pager_process->env_array, "LV=-c");
76}
77
78void setup_pager(void)
79{
80 const char *pager = git_pager(isatty(1));
81
82 if (!pager)
83 return;
84
85 /*
86 * force computing the width of the terminal before we redirect
87 * the standard output to the pager.
88 */
89 (void) term_columns();
90
91 setenv("GIT_PAGER_IN_USE", "true", 1);
92
93 /* spawn the pager */
94 prepare_pager_args(&pager_process, pager);
95 pager_process.in = -1;
96 argv_array_push(&pager_process.env_array, "GIT_PAGER_IN_USE");
97 if (start_command(&pager_process))
98 return;
99
100 /* original process continues, but writes to the pipe */
101 dup2(pager_process.in, 1);
102 if (isatty(2))
103 dup2(pager_process.in, 2);
104 close(pager_process.in);
105
106 /* this makes sure that the parent terminates after the pager */
107 sigchain_push_common(wait_for_pager_signal);
108 atexit(wait_for_pager_atexit);
109}
110
111int pager_in_use(void)
112{
113 const char *env;
114 env = getenv("GIT_PAGER_IN_USE");
115 return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
116}
117
118/*
119 * Return cached value (if set) or $COLUMNS environment variable (if
120 * set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
121 * and default to 80 if all else fails.
122 */
123int term_columns(void)
124{
125 static int term_columns_at_startup;
126
127 char *col_string;
128 int n_cols;
129
130 if (term_columns_at_startup)
131 return term_columns_at_startup;
132
133 term_columns_at_startup = 80;
134
135 col_string = getenv("COLUMNS");
136 if (col_string && (n_cols = atoi(col_string)) > 0)
137 term_columns_at_startup = n_cols;
138#ifdef TIOCGWINSZ
139 else {
140 struct winsize ws;
141 if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
142 term_columns_at_startup = ws.ws_col;
143 }
144#endif
145
146 return term_columns_at_startup;
147}
148
149/*
150 * How many columns do we need to show this number in decimal?
151 */
152int decimal_width(uintmax_t number)
153{
154 int width;
155
156 for (width = 1; number >= 10; width++)
157 number /= 10;
158 return width;
159}
160
161/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
162int check_pager_config(const char *cmd)
163{
164 int want = -1;
165 struct strbuf key = STRBUF_INIT;
166 const char *value = NULL;
167 strbuf_addf(&key, "pager.%s", cmd);
168 if (git_config_key_is_valid(key.buf) &&
169 !git_config_get_value(key.buf, &value)) {
170 int b = git_config_maybe_bool(key.buf, value);
171 if (b >= 0)
172 want = b;
173 else {
174 want = 1;
175 pager_program = xstrdup(value);
176 }
177 }
178 strbuf_release(&key);
179 return want;
180}