Documentation/stash: remove mention of git reset --hard
[git.git] / pager.c
blobae79643363091f4967097bdff6e009ea4c7df5e0
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 static struct child_process pager_process = CHILD_PROCESS_INIT;
10 static const char *pager_program;
12 static void wait_for_pager(int in_signal)
14 if (!in_signal) {
15 fflush(stdout);
16 fflush(stderr);
18 /* signal EOF to pager */
19 close(1);
20 close(2);
21 if (in_signal)
22 finish_command_in_signal(&pager_process);
23 else
24 finish_command(&pager_process);
27 static void wait_for_pager_atexit(void)
29 wait_for_pager(0);
32 static void wait_for_pager_signal(int signo)
34 wait_for_pager(1);
35 sigchain_pop(signo);
36 raise(signo);
39 static int core_pager_config(const char *var, const char *value, void *data)
41 if (!strcmp(var, "core.pager"))
42 return git_config_string(&pager_program, var, value);
43 return 0;
46 static void read_early_config(config_fn_t cb, void *data)
48 git_config_with_options(cb, data, NULL, 1);
51 * Note that this is a really dirty hack that does the wrong thing in
52 * many cases. The crux of the problem is that we cannot run
53 * setup_git_directory() early on in git's setup, so we have no idea if
54 * we are in a repository or not, and therefore are not sure whether
55 * and how to read repository-local config.
57 * So if we _aren't_ in a repository (or we are but we would reject its
58 * core.repositoryformatversion), we'll read whatever is in .git/config
59 * blindly. Similarly, if we _are_ in a repository, but not at the
60 * root, we'll fail to find .git/config (because it's really
61 * ../.git/config, etc). See t7006 for a complete set of failures.
63 * However, we have historically provided this hack because it does
64 * work some of the time (namely when you are at the top-level of a
65 * valid repository), and would rarely make things worse (i.e., you do
66 * not generally have a .git/config file sitting around).
68 if (!startup_info->have_repository) {
69 struct git_config_source repo_config;
71 memset(&repo_config, 0, sizeof(repo_config));
72 repo_config.file = ".git/config";
73 git_config_with_options(cb, data, &repo_config, 1);
77 const char *git_pager(int stdout_is_tty)
79 const char *pager;
81 if (!stdout_is_tty)
82 return NULL;
84 pager = getenv("GIT_PAGER");
85 if (!pager) {
86 if (!pager_program)
87 read_early_config(core_pager_config, NULL);
88 pager = pager_program;
90 if (!pager)
91 pager = getenv("PAGER");
92 if (!pager)
93 pager = DEFAULT_PAGER;
94 if (!*pager || !strcmp(pager, "cat"))
95 pager = NULL;
97 return pager;
100 static void setup_pager_env(struct argv_array *env)
102 const char **argv;
103 int i;
104 char *pager_env = xstrdup(PAGER_ENV);
105 int n = split_cmdline(pager_env, &argv);
107 if (n < 0)
108 die("malformed build-time PAGER_ENV: %s",
109 split_cmdline_strerror(n));
111 for (i = 0; i < n; i++) {
112 char *cp = strchr(argv[i], '=');
114 if (!cp)
115 die("malformed build-time PAGER_ENV");
117 *cp = '\0';
118 if (!getenv(argv[i])) {
119 *cp = '=';
120 argv_array_push(env, argv[i]);
123 free(pager_env);
124 free(argv);
127 void prepare_pager_args(struct child_process *pager_process, const char *pager)
129 argv_array_push(&pager_process->args, pager);
130 pager_process->use_shell = 1;
131 setup_pager_env(&pager_process->env_array);
134 void setup_pager(void)
136 const char *pager = git_pager(isatty(1));
138 if (!pager)
139 return;
142 * force computing the width of the terminal before we redirect
143 * the standard output to the pager.
145 (void) term_columns();
147 setenv("GIT_PAGER_IN_USE", "true", 1);
149 /* spawn the pager */
150 prepare_pager_args(&pager_process, pager);
151 pager_process.in = -1;
152 argv_array_push(&pager_process.env_array, "GIT_PAGER_IN_USE");
153 if (start_command(&pager_process))
154 return;
156 /* original process continues, but writes to the pipe */
157 dup2(pager_process.in, 1);
158 if (isatty(2))
159 dup2(pager_process.in, 2);
160 close(pager_process.in);
162 /* this makes sure that the parent terminates after the pager */
163 sigchain_push_common(wait_for_pager_signal);
164 atexit(wait_for_pager_atexit);
167 int pager_in_use(void)
169 const char *env;
170 env = getenv("GIT_PAGER_IN_USE");
171 return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
175 * Return cached value (if set) or $COLUMNS environment variable (if
176 * set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
177 * and default to 80 if all else fails.
179 int term_columns(void)
181 static int term_columns_at_startup;
183 char *col_string;
184 int n_cols;
186 if (term_columns_at_startup)
187 return term_columns_at_startup;
189 term_columns_at_startup = 80;
191 col_string = getenv("COLUMNS");
192 if (col_string && (n_cols = atoi(col_string)) > 0)
193 term_columns_at_startup = n_cols;
194 #ifdef TIOCGWINSZ
195 else {
196 struct winsize ws;
197 if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
198 term_columns_at_startup = ws.ws_col;
200 #endif
202 return term_columns_at_startup;
206 * How many columns do we need to show this number in decimal?
208 int decimal_width(uintmax_t number)
210 int width;
212 for (width = 1; number >= 10; width++)
213 number /= 10;
214 return width;
217 struct pager_command_config_data {
218 const char *cmd;
219 int want;
220 char *value;
223 static int pager_command_config(const char *var, const char *value, void *vdata)
225 struct pager_command_config_data *data = vdata;
226 const char *cmd;
228 if (skip_prefix(var, "pager.", &cmd) && !strcmp(cmd, data->cmd)) {
229 int b = git_config_maybe_bool(var, value);
230 if (b >= 0)
231 data->want = b;
232 else {
233 data->want = 1;
234 data->value = xstrdup(value);
238 return 0;
241 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
242 int check_pager_config(const char *cmd)
244 struct pager_command_config_data data;
246 data.cmd = cmd;
247 data.want = -1;
248 data.value = NULL;
250 read_early_config(pager_command_config, &data);
252 if (data.value)
253 pager_program = data.value;
254 return data.want;