transport-helper: drop read/write errno checks
[git.git] / pager.c
bloba768797fcfcc44de4dbe4d983a45ade8c81b2e1c
1 #include "cache.h"
2 #include "config.h"
3 #include "run-command.h"
4 #include "sigchain.h"
5 #include "alias.h"
7 #ifndef DEFAULT_PAGER
8 #define DEFAULT_PAGER "less"
9 #endif
11 static struct child_process pager_process = CHILD_PROCESS_INIT;
12 static const char *pager_program;
14 static void wait_for_pager(int in_signal)
16 if (!in_signal) {
17 fflush(stdout);
18 fflush(stderr);
20 /* signal EOF to pager */
21 close(1);
22 close(2);
23 if (in_signal)
24 finish_command_in_signal(&pager_process);
25 else
26 finish_command(&pager_process);
29 static void wait_for_pager_atexit(void)
31 wait_for_pager(0);
34 static void wait_for_pager_signal(int signo)
36 wait_for_pager(1);
37 sigchain_pop(signo);
38 raise(signo);
41 static int core_pager_config(const char *var, const char *value, void *data)
43 if (!strcmp(var, "core.pager"))
44 return git_config_string(&pager_program, var, value);
45 return 0;
48 const char *git_pager(int stdout_is_tty)
50 const char *pager;
52 if (!stdout_is_tty)
53 return NULL;
55 pager = getenv("GIT_PAGER");
56 if (!pager) {
57 if (!pager_program)
58 read_early_config(core_pager_config, NULL);
59 pager = pager_program;
61 if (!pager)
62 pager = getenv("PAGER");
63 if (!pager)
64 pager = DEFAULT_PAGER;
65 if (!*pager || !strcmp(pager, "cat"))
66 pager = NULL;
68 return pager;
71 static void setup_pager_env(struct argv_array *env)
73 const char **argv;
74 int i;
75 char *pager_env = xstrdup(PAGER_ENV);
76 int n = split_cmdline(pager_env, &argv);
78 if (n < 0)
79 die("malformed build-time PAGER_ENV: %s",
80 split_cmdline_strerror(n));
82 for (i = 0; i < n; i++) {
83 char *cp = strchr(argv[i], '=');
85 if (!cp)
86 die("malformed build-time PAGER_ENV");
88 *cp = '\0';
89 if (!getenv(argv[i])) {
90 *cp = '=';
91 argv_array_push(env, argv[i]);
94 free(pager_env);
95 free(argv);
98 void prepare_pager_args(struct child_process *pager_process, const char *pager)
100 argv_array_push(&pager_process->args, pager);
101 pager_process->use_shell = 1;
102 setup_pager_env(&pager_process->env_array);
105 void setup_pager(void)
107 const char *pager = git_pager(isatty(1));
109 if (!pager)
110 return;
113 * After we redirect standard output, we won't be able to use an ioctl
114 * to get the terminal size. Let's grab it now, and then set $COLUMNS
115 * to communicate it to any sub-processes.
118 char buf[64];
119 xsnprintf(buf, sizeof(buf), "%d", term_columns());
120 setenv("COLUMNS", buf, 0);
123 setenv("GIT_PAGER_IN_USE", "true", 1);
125 /* spawn the pager */
126 prepare_pager_args(&pager_process, pager);
127 pager_process.in = -1;
128 argv_array_push(&pager_process.env_array, "GIT_PAGER_IN_USE");
129 if (start_command(&pager_process))
130 return;
132 /* original process continues, but writes to the pipe */
133 dup2(pager_process.in, 1);
134 if (isatty(2))
135 dup2(pager_process.in, 2);
136 close(pager_process.in);
138 /* this makes sure that the parent terminates after the pager */
139 sigchain_push_common(wait_for_pager_signal);
140 atexit(wait_for_pager_atexit);
143 int pager_in_use(void)
145 return git_env_bool("GIT_PAGER_IN_USE", 0);
149 * Return cached value (if set) or $COLUMNS environment variable (if
150 * set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
151 * and default to 80 if all else fails.
153 int term_columns(void)
155 static int term_columns_at_startup;
157 char *col_string;
158 int n_cols;
160 if (term_columns_at_startup)
161 return term_columns_at_startup;
163 term_columns_at_startup = 80;
165 col_string = getenv("COLUMNS");
166 if (col_string && (n_cols = atoi(col_string)) > 0)
167 term_columns_at_startup = n_cols;
168 #ifdef TIOCGWINSZ
169 else {
170 struct winsize ws;
171 if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
172 term_columns_at_startup = ws.ws_col;
174 #endif
176 return term_columns_at_startup;
180 * How many columns do we need to show this number in decimal?
182 int decimal_width(uintmax_t number)
184 int width;
186 for (width = 1; number >= 10; width++)
187 number /= 10;
188 return width;
191 struct pager_command_config_data {
192 const char *cmd;
193 int want;
194 char *value;
197 static int pager_command_config(const char *var, const char *value, void *vdata)
199 struct pager_command_config_data *data = vdata;
200 const char *cmd;
202 if (skip_prefix(var, "pager.", &cmd) && !strcmp(cmd, data->cmd)) {
203 int b = git_parse_maybe_bool(value);
204 if (b >= 0)
205 data->want = b;
206 else {
207 data->want = 1;
208 data->value = xstrdup(value);
212 return 0;
215 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
216 int check_pager_config(const char *cmd)
218 struct pager_command_config_data data;
220 data.cmd = cmd;
221 data.want = -1;
222 data.value = NULL;
224 read_early_config(pager_command_config, &data);
226 if (data.value)
227 pager_program = data.value;
228 return data.want;