Merge branch 'kb/perf-trace'
[git.git] / pager.c
blob8b5cbc56e4fd57a1b9d2cad3e668df4c508a7b17
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 struct pager_config {
10 const char *cmd;
11 int want;
12 char *value;
16 * This is split up from the rest of git so that we can do
17 * something different on Windows.
20 static const char *pager_argv[] = { NULL, NULL };
21 static struct child_process pager_process;
23 static void wait_for_pager(void)
25 fflush(stdout);
26 fflush(stderr);
27 /* signal EOF to pager */
28 close(1);
29 close(2);
30 finish_command(&pager_process);
33 static void wait_for_pager_signal(int signo)
35 wait_for_pager();
36 sigchain_pop(signo);
37 raise(signo);
40 const char *git_pager(int stdout_is_tty)
42 const char *pager;
44 if (!stdout_is_tty)
45 return NULL;
47 pager = getenv("GIT_PAGER");
48 if (!pager) {
49 if (!pager_program)
50 git_config(git_default_config, NULL);
51 pager = pager_program;
53 if (!pager)
54 pager = getenv("PAGER");
55 if (!pager)
56 pager = DEFAULT_PAGER;
57 if (!*pager || !strcmp(pager, "cat"))
58 pager = NULL;
60 return pager;
63 void setup_pager(void)
65 const char *pager = git_pager(isatty(1));
67 if (!pager)
68 return;
71 * force computing the width of the terminal before we redirect
72 * the standard output to the pager.
74 (void) term_columns();
76 setenv("GIT_PAGER_IN_USE", "true", 1);
78 /* spawn the pager */
79 pager_argv[0] = pager;
80 pager_process.use_shell = 1;
81 pager_process.argv = pager_argv;
82 pager_process.in = -1;
83 if (!getenv("LESS") || !getenv("LV")) {
84 static const char *env[3];
85 int i = 0;
87 if (!getenv("LESS"))
88 env[i++] = "LESS=FRX";
89 if (!getenv("LV"))
90 env[i++] = "LV=-c";
91 env[i] = NULL;
92 pager_process.env = env;
94 if (start_command(&pager_process))
95 return;
97 /* original process continues, but writes to the pipe */
98 dup2(pager_process.in, 1);
99 if (isatty(2))
100 dup2(pager_process.in, 2);
101 close(pager_process.in);
103 /* this makes sure that the parent terminates after the pager */
104 sigchain_push_common(wait_for_pager_signal);
105 atexit(wait_for_pager);
108 int pager_in_use(void)
110 const char *env;
111 env = getenv("GIT_PAGER_IN_USE");
112 return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
116 * Return cached value (if set) or $COLUMNS environment variable (if
117 * set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
118 * and default to 80 if all else fails.
120 int term_columns(void)
122 static int term_columns_at_startup;
124 char *col_string;
125 int n_cols;
127 if (term_columns_at_startup)
128 return term_columns_at_startup;
130 term_columns_at_startup = 80;
132 col_string = getenv("COLUMNS");
133 if (col_string && (n_cols = atoi(col_string)) > 0)
134 term_columns_at_startup = n_cols;
135 #ifdef TIOCGWINSZ
136 else {
137 struct winsize ws;
138 if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
139 term_columns_at_startup = ws.ws_col;
141 #endif
143 return term_columns_at_startup;
147 * How many columns do we need to show this number in decimal?
149 int decimal_width(int number)
151 int i, width;
153 for (width = 1, i = 10; i <= number; width++)
154 i *= 10;
155 return width;
158 static int pager_command_config(const char *var, const char *value, void *data)
160 struct pager_config *c = data;
161 if (starts_with(var, "pager.") && !strcmp(var + 6, c->cmd)) {
162 int b = git_config_maybe_bool(var, value);
163 if (b >= 0)
164 c->want = b;
165 else {
166 c->want = 1;
167 c->value = xstrdup(value);
170 return 0;
173 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
174 int check_pager_config(const char *cmd)
176 struct pager_config c;
177 c.cmd = cmd;
178 c.want = -1;
179 c.value = NULL;
180 git_config(pager_command_config, &c);
181 if (c.value)
182 pager_program = c.value;
183 return c.want;