diff options
Diffstat (limited to 'pager.c')
| -rw-r--r-- | pager.c | 159 |
1 files changed, 117 insertions, 42 deletions
@@ -1,13 +1,18 @@ #include "cache.h" +#include "run-command.h" +#include "sigchain.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 int spawned_pager; - -static void run_pager(const char *pager) +#ifndef WIN32 +static void pager_preexec(void) { /* * Work around bug in "less" by not starting it until we @@ -18,19 +23,37 @@ static void run_pager(const char *pager) FD_ZERO(&in); FD_SET(0, &in); select(1, &in, NULL, &in, NULL); +} +#endif - execlp(pager, pager, NULL); - execl("/bin/sh", "sh", "-c", pager, NULL); +static const char *pager_argv[] = { NULL, NULL }; +static struct child_process pager_process; + +static void wait_for_pager(void) +{ + fflush(stdout); + fflush(stderr); + /* signal EOF to pager */ + close(1); + close(2); + finish_command(&pager_process); } -void setup_pager(void) +static void wait_for_pager_signal(int signo) { - pid_t pid; - int fd[2]; - const char *pager = getenv("GIT_PAGER"); + wait_for_pager(); + sigchain_pop(signo); + raise(signo); +} - if (!isatty(1)) - return; +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) git_config(git_default_config, NULL); @@ -39,48 +62,100 @@ void setup_pager(void) if (!pager) pager = getenv("PAGER"); if (!pager) - pager = "less"; + pager = DEFAULT_PAGER; else if (!*pager || !strcmp(pager, "cat")) - return; + pager = NULL; - spawned_pager = 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]); - return; - } +void setup_pager(void) +{ + const char *pager = git_pager(isatty(1)); - /* return in the child */ - if (!pid) { - dup2(fd[1], 1); - dup2(fd[1], 2); - close(fd[0]); - close(fd[1]); + if (!pager || pager_in_use()) 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 */ + pager_argv[0] = pager; + pager_process.use_shell = 1; + pager_process.argv = pager_argv; + pager_process.in = -1; + if (!getenv("LESS")) { + static const char *env[] = { "LESS=FRSX", NULL }; + pager_process.env = env; } +#ifndef WIN32 + pager_process.preexec_cb = pager_preexec; +#endif + if (start_command(&pager_process)) + return; - /* The original process turns into the PAGER */ - dup2(fd[0], 0); - close(fd[0]); - close(fd[1]); + /* 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); - setenv("LESS", "FRSX", 0); - run_pager(pager); - die("unable to execute pager '%s'", pager); - exit(255); + /* 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; - - if (spawned_pager) - return 1; - 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 + + return term_columns_at_startup; +} + +/* + * How many columns do we need to show this number in decimal? + */ +int decimal_width(int number) +{ + int i, width; + + for (width = 1, i = 10; i <= number; width++) + i *= 10; + return width; +} |