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e8320f350f
Commit 35ce862 (pager: Work around window resizing bug in
'less', 2007-01-24) causes git's pager sub-process to wait
to receive input after forking but before exec-ing the
pager. To handle this, run-command had to grow a "pre-exec
callback" feature. Unfortunately, this feature does not work
at all on Windows (where we do not fork), and interacts
poorly with run-command's parent notification system. Its
use should be discouraged.
The bug in less was fixed in version 406, which was released
in June 2007. It is probably safe at this point to remove
our workaround. That lets us rip out the preexec_cb feature
entirely.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
143 lines
2.8 KiB
C
143 lines
2.8 KiB
C
#include "cache.h"
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#include "run-command.h"
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#include "sigchain.h"
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#ifndef DEFAULT_PAGER
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#define DEFAULT_PAGER "less"
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#endif
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/*
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* This is split up from the rest of git so that we can do
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* something different on Windows.
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*/
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static const char *pager_argv[] = { NULL, NULL };
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static struct child_process pager_process;
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static void wait_for_pager(void)
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{
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fflush(stdout);
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fflush(stderr);
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/* signal EOF to pager */
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close(1);
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close(2);
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finish_command(&pager_process);
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}
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static void wait_for_pager_signal(int signo)
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{
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wait_for_pager();
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sigchain_pop(signo);
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raise(signo);
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}
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const char *git_pager(int stdout_is_tty)
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{
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const char *pager;
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if (!stdout_is_tty)
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return NULL;
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pager = getenv("GIT_PAGER");
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if (!pager) {
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if (!pager_program)
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git_config(git_default_config, NULL);
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pager = pager_program;
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}
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if (!pager)
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pager = getenv("PAGER");
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if (!pager)
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pager = DEFAULT_PAGER;
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else if (!*pager || !strcmp(pager, "cat"))
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pager = NULL;
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return pager;
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}
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void setup_pager(void)
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{
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const char *pager = git_pager(isatty(1));
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if (!pager || pager_in_use())
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return;
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/*
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* force computing the width of the terminal before we redirect
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* the standard output to the pager.
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*/
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(void) term_columns();
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setenv("GIT_PAGER_IN_USE", "true", 1);
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/* spawn the pager */
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pager_argv[0] = pager;
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pager_process.use_shell = 1;
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pager_process.argv = pager_argv;
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pager_process.in = -1;
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if (!getenv("LESS")) {
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static const char *env[] = { "LESS=FRSX", NULL };
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pager_process.env = env;
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}
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if (start_command(&pager_process))
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return;
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/* original process continues, but writes to the pipe */
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dup2(pager_process.in, 1);
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if (isatty(2))
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dup2(pager_process.in, 2);
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close(pager_process.in);
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/* this makes sure that the parent terminates after the pager */
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sigchain_push_common(wait_for_pager_signal);
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atexit(wait_for_pager);
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}
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int pager_in_use(void)
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{
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const char *env;
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env = getenv("GIT_PAGER_IN_USE");
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return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
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}
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/*
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* Return cached value (if set) or $COLUMNS environment variable (if
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* set and positive) or ioctl(1, TIOCGWINSZ).ws_col (if positive),
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* and default to 80 if all else fails.
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*/
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int term_columns(void)
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{
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static int term_columns_at_startup;
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char *col_string;
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int n_cols;
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if (term_columns_at_startup)
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return term_columns_at_startup;
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term_columns_at_startup = 80;
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col_string = getenv("COLUMNS");
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if (col_string && (n_cols = atoi(col_string)) > 0)
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term_columns_at_startup = n_cols;
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#ifdef TIOCGWINSZ
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else {
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struct winsize ws;
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if (!ioctl(1, TIOCGWINSZ, &ws) && ws.ws_col)
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term_columns_at_startup = ws.ws_col;
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}
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#endif
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return term_columns_at_startup;
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}
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/*
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* How many columns do we need to show this number in decimal?
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*/
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int decimal_width(int number)
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{
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int i, width;
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for (width = 1, i = 10; i <= number; width++)
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i *= 10;
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return width;
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}
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