Merge branch 'mc/commit-doc-grammofix' into maint
[git.git] / pager.c
blob98b26823c9e0c0bd220a7a41a97675626c8e65ec
1 #include "cache.h"
2 #include "run-command.h"
3 #include "sigchain.h"
5 #ifndef DEFAULT_PAGER
6 #define DEFAULT_PAGER "less"
7 #endif
9 /*
10 * This is split up from the rest of git so that we can do
11 * something different on Windows.
14 static const char *pager_argv[] = { NULL, NULL };
15 static struct child_process pager_process = CHILD_PROCESS_INIT;
17 static void wait_for_pager(void)
19 fflush(stdout);
20 fflush(stderr);
21 /* signal EOF to pager */
22 close(1);
23 close(2);
24 finish_command(&pager_process);
27 static void wait_for_pager_signal(int signo)
29 wait_for_pager();
30 sigchain_pop(signo);
31 raise(signo);
34 const char *git_pager(int stdout_is_tty)
36 const char *pager;
38 if (!stdout_is_tty)
39 return NULL;
41 pager = getenv("GIT_PAGER");
42 if (!pager) {
43 if (!pager_program)
44 git_config(git_default_config, NULL);
45 pager = pager_program;
47 if (!pager)
48 pager = getenv("PAGER");
49 if (!pager)
50 pager = DEFAULT_PAGER;
51 if (!*pager || !strcmp(pager, "cat"))
52 pager = NULL;
54 return pager;
57 void setup_pager(void)
59 const char *pager = git_pager(isatty(1));
61 if (!pager)
62 return;
65 * force computing the width of the terminal before we redirect
66 * the standard output to the pager.
68 (void) term_columns();
70 setenv("GIT_PAGER_IN_USE", "true", 1);
72 /* spawn the pager */
73 pager_argv[0] = pager;
74 pager_process.use_shell = 1;
75 pager_process.argv = pager_argv;
76 pager_process.in = -1;
77 if (!getenv("LESS"))
78 argv_array_push(&pager_process.env_array, "LESS=FRX");
79 if (!getenv("LV"))
80 argv_array_push(&pager_process.env_array, "LV=-c");
81 if (start_command(&pager_process))
82 return;
84 /* original process continues, but writes to the pipe */
85 dup2(pager_process.in, 1);
86 if (isatty(2))
87 dup2(pager_process.in, 2);
88 close(pager_process.in);
90 /* this makes sure that the parent terminates after the pager */
91 sigchain_push_common(wait_for_pager_signal);
92 atexit(wait_for_pager);
95 int pager_in_use(void)
97 const char *env;
98 env = getenv("GIT_PAGER_IN_USE");
99 return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
103 * Return cached value (if set) or $COLUMNS environment variable (if
104 * set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
105 * and default to 80 if all else fails.
107 int term_columns(void)
109 static int term_columns_at_startup;
111 char *col_string;
112 int n_cols;
114 if (term_columns_at_startup)
115 return term_columns_at_startup;
117 term_columns_at_startup = 80;
119 col_string = getenv("COLUMNS");
120 if (col_string && (n_cols = atoi(col_string)) > 0)
121 term_columns_at_startup = n_cols;
122 #ifdef TIOCGWINSZ
123 else {
124 struct winsize ws;
125 if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
126 term_columns_at_startup = ws.ws_col;
128 #endif
130 return term_columns_at_startup;
134 * How many columns do we need to show this number in decimal?
136 int decimal_width(uintmax_t number)
138 int width;
140 for (width = 1; number >= 10; width++)
141 number /= 10;
142 return width;
145 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
146 int check_pager_config(const char *cmd)
148 int want = -1;
149 struct strbuf key = STRBUF_INIT;
150 const char *value = NULL;
151 strbuf_addf(&key, "pager.%s", cmd);
152 if (!git_config_get_value(key.buf, &value)) {
153 int b = git_config_maybe_bool(key.buf, value);
154 if (b >= 0)
155 want = b;
156 else {
157 want = 1;
158 pager_program = xstrdup(value);
161 strbuf_release(&key);
162 return want;