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git/pager.c
Junio C Hamano 6a5ff7acb5 Merge branch 'jk/pager-in-use'
Code clean-up.

* jk/pager-in-use:
  pager_in_use: use git_env_bool()
2017-03-28 14:05:59 -07:00

223 lines
4.3 KiB
C

#include "cache.h"
#include "run-command.h"
#include "sigchain.h"
#ifndef DEFAULT_PAGER
#define DEFAULT_PAGER "less"
#endif
static struct child_process pager_process = CHILD_PROCESS_INIT;
static const char *pager_program;
static void wait_for_pager(int in_signal)
{
if (!in_signal) {
fflush(stdout);
fflush(stderr);
}
/* signal EOF to pager */
close(1);
close(2);
if (in_signal)
finish_command_in_signal(&pager_process);
else
finish_command(&pager_process);
}
static void wait_for_pager_atexit(void)
{
wait_for_pager(0);
}
static void wait_for_pager_signal(int signo)
{
wait_for_pager(1);
sigchain_pop(signo);
raise(signo);
}
static int core_pager_config(const char *var, const char *value, void *data)
{
if (!strcmp(var, "core.pager"))
return git_config_string(&pager_program, var, value);
return 0;
}
const char *git_pager(int stdout_is_tty)
{
const char *pager;
if (!stdout_is_tty)
return NULL;
pager = getenv("GIT_PAGER");
if (!pager) {
if (!pager_program)
read_early_config(core_pager_config, NULL);
pager = pager_program;
}
if (!pager)
pager = getenv("PAGER");
if (!pager)
pager = DEFAULT_PAGER;
if (!*pager || !strcmp(pager, "cat"))
pager = NULL;
return pager;
}
static void setup_pager_env(struct argv_array *env)
{
const char **argv;
int i;
char *pager_env = xstrdup(PAGER_ENV);
int n = split_cmdline(pager_env, &argv);
if (n < 0)
die("malformed build-time PAGER_ENV: %s",
split_cmdline_strerror(n));
for (i = 0; i < n; i++) {
char *cp = strchr(argv[i], '=');
if (!cp)
die("malformed build-time PAGER_ENV");
*cp = '\0';
if (!getenv(argv[i])) {
*cp = '=';
argv_array_push(env, argv[i]);
}
}
free(pager_env);
free(argv);
}
void prepare_pager_args(struct child_process *pager_process, const char *pager)
{
argv_array_push(&pager_process->args, pager);
pager_process->use_shell = 1;
setup_pager_env(&pager_process->env_array);
}
void setup_pager(void)
{
const char *pager = git_pager(isatty(1));
if (!pager)
return;
/*
* force computing the width of the terminal before we redirect
* the standard output to the pager.
*/
(void) term_columns();
setenv("GIT_PAGER_IN_USE", "true", 1);
/* spawn the pager */
prepare_pager_args(&pager_process, pager);
pager_process.in = -1;
argv_array_push(&pager_process.env_array, "GIT_PAGER_IN_USE");
if (start_command(&pager_process))
return;
/* original process continues, but writes to the pipe */
dup2(pager_process.in, 1);
if (isatty(2))
dup2(pager_process.in, 2);
close(pager_process.in);
/* this makes sure that the parent terminates after the pager */
sigchain_push_common(wait_for_pager_signal);
atexit(wait_for_pager_atexit);
}
int pager_in_use(void)
{
return git_env_bool("GIT_PAGER_IN_USE", 0);
}
/*
* Return cached value (if set) or $COLUMNS environment variable (if
* set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
* and default to 80 if all else fails.
*/
int term_columns(void)
{
static int term_columns_at_startup;
char *col_string;
int n_cols;
if (term_columns_at_startup)
return term_columns_at_startup;
term_columns_at_startup = 80;
col_string = getenv("COLUMNS");
if (col_string && (n_cols = atoi(col_string)) > 0)
term_columns_at_startup = n_cols;
#ifdef TIOCGWINSZ
else {
struct winsize ws;
if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
term_columns_at_startup = ws.ws_col;
}
#endif
return term_columns_at_startup;
}
/*
* How many columns do we need to show this number in decimal?
*/
int decimal_width(uintmax_t number)
{
int width;
for (width = 1; number >= 10; width++)
number /= 10;
return width;
}
struct pager_command_config_data {
const char *cmd;
int want;
char *value;
};
static int pager_command_config(const char *var, const char *value, void *vdata)
{
struct pager_command_config_data *data = vdata;
const char *cmd;
if (skip_prefix(var, "pager.", &cmd) && !strcmp(cmd, data->cmd)) {
int b = git_config_maybe_bool(var, value);
if (b >= 0)
data->want = b;
else {
data->want = 1;
data->value = xstrdup(value);
}
}
return 0;
}
/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
int check_pager_config(const char *cmd)
{
struct pager_command_config_data data;
data.cmd = cmd;
data.want = -1;
data.value = NULL;
read_early_config(pager_command_config, &data);
if (data.value)
pager_program = data.value;
return data.want;
}