pager.c

   1 #include "cache.h"
   2
   3 #include <sys/select.h>
   4
   5 /*
   6  * This is split up from the rest of git so that we might do
   7  * something different on Windows, for example.
   8  */
   9
  10 static 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
  26 void 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                 pager = pager_program;
  36         if (!pager)
  37                 pager = getenv("PAGER");
  38         if (!pager)
  39                 pager = "less";
  40         else if (!*pager || !strcmp(pager, "cat"))
  41                 return;
  42
  43         pager_in_use = 1; /* means we are emitting to terminal */
  44
  45         if (pipe(fd) < 0)
  46                 return;
  47         pid = fork();
  48         if (pid < 0) {
  49                 close(fd[0]);
  50                 close(fd[1]);
  51                 return;
  52         }
  53
  54         /* return in the child */
  55         if (!pid) {
  56                 dup2(fd[1], 1);
  57                 close(fd[0]);
  58                 close(fd[1]);
  59                 return;
  60         }
  61
  62         /* The original process turns into the PAGER */
  63         dup2(fd[0], 0);
  64         close(fd[0]);
  65         close(fd[1]);
  66
  67         setenv("LESS", "FRSX", 0);
  68         run_pager(pager);
  69         die("unable to execute pager '%s'", pager);
  70         exit(255);
  71 }