pager.con commit git-p4: Unset P4DIFF environment variable when using 'p4 -du diff' (67abd41)
   1#include "cache.h"
   2
   3/*
   4 * This is split up from the rest of git so that we might do
   5 * something different on Windows, for example.
   6 */
   7
   8static int spawned_pager;
   9
  10static void run_pager(const char *pager)
  11{
  12        /*
  13         * Work around bug in "less" by not starting it until we
  14         * have real input
  15         */
  16        fd_set in;
  17
  18        FD_ZERO(&in);
  19        FD_SET(0, &in);
  20        select(1, &in, NULL, &in, NULL);
  21
  22        execlp(pager, pager, NULL);
  23        execl("/bin/sh", "sh", "-c", pager, NULL);
  24}
  25
  26void setup_pager(void)
  27{
  28        pid_t pid;
  29        int fd[2];
  30        const char *pager = getenv("GIT_PAGER");
  31
  32        if (!isatty(1))
  33                return;
  34        if (!pager) {
  35                if (!pager_program)
  36                        git_config(git_default_config);
  37                pager = pager_program;
  38        }
  39        if (!pager)
  40                pager = getenv("PAGER");
  41        if (!pager)
  42                pager = "less";
  43        else if (!*pager || !strcmp(pager, "cat"))
  44                return;
  45
  46        spawned_pager = 1; /* means we are emitting to terminal */
  47
  48        if (pipe(fd) < 0)
  49                return;
  50        pid = fork();
  51        if (pid < 0) {
  52                close(fd[0]);
  53                close(fd[1]);
  54                return;
  55        }
  56
  57        /* return in the child */
  58        if (!pid) {
  59                dup2(fd[1], 1);
  60                dup2(fd[1], 2);
  61                close(fd[0]);
  62                close(fd[1]);
  63                return;
  64        }
  65
  66        /* The original process turns into the PAGER */
  67        dup2(fd[0], 0);
  68        close(fd[0]);
  69        close(fd[1]);
  70
  71        setenv("LESS", "FRSX", 0);
  72        run_pager(pager);
  73        die("unable to execute pager '%s'", pager);
  74        exit(255);
  75}
  76
  77int pager_in_use(void)
  78{
  79        const char *env;
  80
  81        if (spawned_pager)
  82                return 1;
  83
  84        env = getenv("GIT_PAGER_IN_USE");
  85        return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
  86}