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 = getenv("PAGER");
  36         if (!pager)
  37                 pager = "less";
  38         else if (!*pager || !strcmp(pager, "cat"))
  39                 return;
  40
  41         pager_in_use = 1; /* means we are emitting to terminal */
  42
  43         if (pipe(fd) < 0)
  44                 return;
  45         pid = fork();
  46         if (pid < 0) {
  47                 close(fd[0]);
  48                 close(fd[1]);
  49                 return;
  50         }
  51
  52         /* return in the child */
  53         if (!pid) {
  54                 dup2(fd[1], 1);
  55                 close(fd[0]);
  56                 close(fd[1]);
  57                 return;
  58         }
  59
  60         /* The original process turns into the PAGER */
  61         dup2(fd[0], 0);
  62         close(fd[0]);
  63         close(fd[1]);
  64
  65         setenv("LESS", "FRSX", 0);
  66         run_pager(pager);
  67         die("unable to execute pager '%s'", pager);
  68         exit(255);
  69 }