Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "run-command.h"
   3#include "sigchain.h"
   4
   5/*
   6 * This is split up from the rest of git so that we can do
   7 * something different on Windows.
   8 */
   9
  10static int spawned_pager;
  11
  12#ifndef WIN32
  13static void pager_preexec(void)
  14{
  15        /*
  16         * Work around bug in "less" by not starting it until we
  17         * have real input
  18         */
  19        fd_set in;
  20
  21        FD_ZERO(&in);
  22        FD_SET(0, &in);
  23        select(1, &in, NULL, &in, NULL);
  24}
  25#endif
  26
  27static const char *pager_argv[] = { "sh", "-c", NULL, NULL };
  28static struct child_process pager_process;
  29
  30static void wait_for_pager(void)
  31{
  32        fflush(stdout);
  33        fflush(stderr);
  34        /* signal EOF to pager */
  35        close(1);
  36        close(2);
  37        finish_command(&pager_process);
  38}
  39
  40static void wait_for_pager_signal(int signo)
  41{
  42        wait_for_pager();
  43        sigchain_pop(signo);
  44        raise(signo);
  45}
  46
  47const char *git_pager(void)
  48{
  49        const char *pager;
  50
  51        if (!isatty(1))
  52                return NULL;
  53
  54        pager = getenv("GIT_PAGER");
  55        if (!pager) {
  56                if (!pager_program)
  57                        git_config(git_default_config, NULL);
  58                pager = pager_program;
  59        }
  60        if (!pager)
  61                pager = getenv("PAGER");
  62        if (!pager)
  63                pager = "less";
  64        else if (!*pager || !strcmp(pager, "cat"))
  65                pager = NULL;
  66
  67        return pager;
  68}
  69
  70void setup_pager(void)
  71{
  72        const char *pager = git_pager();
  73
  74        if (!pager)
  75                return;
  76
  77        spawned_pager = 1; /* means we are emitting to terminal */
  78
  79        /* spawn the pager */
  80        pager_argv[2] = pager;
  81        pager_process.argv = pager_argv;
  82        pager_process.in = -1;
  83        if (!getenv("LESS")) {
  84                static const char *env[] = { "LESS=FRSX", NULL };
  85                pager_process.env = env;
  86        }
  87#ifndef WIN32
  88        pager_process.preexec_cb = pager_preexec;
  89#endif
  90        if (start_command(&pager_process))
  91                return;
  92
  93        /* original process continues, but writes to the pipe */
  94        dup2(pager_process.in, 1);
  95        if (isatty(2))
  96                dup2(pager_process.in, 2);
  97        close(pager_process.in);
  98
  99        /* this makes sure that the parent terminates after the pager */
 100        sigchain_push_common(wait_for_pager_signal);
 101        atexit(wait_for_pager);
 102}
 103
 104int pager_in_use(void)
 105{
 106        const char *env;
 107
 108        if (spawned_pager)
 109                return 1;
 110
 111        env = getenv("GIT_PAGER_IN_USE");
 112        return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
 113}