diff options
Diffstat (limited to 'pager.c')
| -rw-r--r-- | pager.c | 186 |
1 files changed, 141 insertions, 45 deletions
@@ -1,69 +1,165 @@ #include "cache.h" +#include "run-command.h" +#include "sigchain.h" -#include <sys/select.h> +#ifndef DEFAULT_PAGER +#define DEFAULT_PAGER "less" +#endif /* - * This is split up from the rest of git so that we might do - * something different on Windows, for example. + * This is split up from the rest of git so that we can do + * something different on Windows. */ -static void run_pager(const char *pager) -{ - /* - * Work around bug in "less" by not starting it until we - * have real input - */ - fd_set in; +static const char *pager_argv[] = { NULL, NULL }; +static struct child_process pager_process = CHILD_PROCESS_INIT; - FD_ZERO(&in); - FD_SET(0, &in); - select(1, &in, NULL, &in, NULL); +static void wait_for_pager(void) +{ + fflush(stdout); + fflush(stderr); + /* signal EOF to pager */ + close(1); + close(2); + finish_command(&pager_process); +} - execlp(pager, pager, NULL); - execl("/bin/sh", "sh", "-c", pager, NULL); +static void wait_for_pager_signal(int signo) +{ + wait_for_pager(); + sigchain_pop(signo); + raise(signo); } -void setup_pager(void) +const char *git_pager(int stdout_is_tty) { - pid_t pid; - int fd[2]; - const char *pager = getenv("GIT_PAGER"); + const char *pager; - if (!isatty(1)) - return; + if (!stdout_is_tty) + return NULL; + + pager = getenv("GIT_PAGER"); + if (!pager) { + if (!pager_program) + git_config(git_default_config, NULL); + pager = pager_program; + } if (!pager) pager = getenv("PAGER"); if (!pager) - pager = "less"; - else if (!*pager || !strcmp(pager, "cat")) - return; + pager = DEFAULT_PAGER; + if (!*pager || !strcmp(pager, "cat")) + pager = NULL; - pager_in_use = 1; /* means we are emitting to terminal */ + return pager; +} - if (pipe(fd) < 0) - return; - pid = fork(); - if (pid < 0) { - close(fd[0]); - close(fd[1]); +void setup_pager(void) +{ + const char *pager = git_pager(isatty(1)); + + if (!pager) return; - } - /* return in the child */ - if (!pid) { - dup2(fd[1], 1); - close(fd[0]); - close(fd[1]); + /* + * 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 */ + pager_argv[0] = pager; + pager_process.use_shell = 1; + pager_process.argv = pager_argv; + pager_process.in = -1; + if (!getenv("LESS")) + argv_array_push(&pager_process.env_array, "LESS=FRX"); + if (!getenv("LV")) + argv_array_push(&pager_process.env_array, "LV=-c"); + 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); +} + +int pager_in_use(void) +{ + const char *env; + env = getenv("GIT_PAGER_IN_USE"); + return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 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 - /* The original process turns into the PAGER */ - dup2(fd[0], 0); - close(fd[0]); - close(fd[1]); + return term_columns_at_startup; +} - setenv("LESS", "FRSX", 0); - run_pager(pager); - die("unable to execute pager '%s'", pager); - exit(255); +/* + * 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; +} + +/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */ +int check_pager_config(const char *cmd) +{ + int want = -1; + struct strbuf key = STRBUF_INIT; + const char *value = NULL; + strbuf_addf(&key, "pager.%s", cmd); + if (git_config_key_is_valid(key.buf) && + !git_config_get_value(key.buf, &value)) { + int b = git_config_maybe_bool(key.buf, value); + if (b >= 0) + want = b; + else { + want = 1; + pager_program = xstrdup(value); + } + } + strbuf_release(&key); + return want; } |