pager.c

   1 #include "cache.h"
   2 #include "spawn-pipe.h"
   3
   4 /*
   5  * This is split up from the rest of git so that we might do
   6  * something different on Windows, for example.
   7  */
   8
   9 #ifndef __MINGW32__
  10 static void run_pager(const char *pager)
  11 {
  12         execlp(pager, pager, NULL);
  13         execl("/bin/sh", "sh", "-c", pager, NULL);
  14 }
  15 #endif
  16
  17 void setup_pager(void)
  18 {
  19 #ifndef __MINGW32__
  20         pid_t pid;
  21 #else
  22         const char *pager_argv[] = { "sh", "-c", NULL, NULL };
  23 #endif
  24         int fd[2];
  25         const char *pager = getenv("GIT_PAGER");
  26
  27         if (!isatty(1))
  28                 return;
  29         if (!pager)
  30                 pager = getenv("PAGER");
  31         if (!pager)
  32                 pager = "less";
  33         else if (!*pager || !strcmp(pager, "cat"))
  34                 return;
  35
  36         pager_in_use = 1; /* means we are emitting to terminal */
  37
  38         if (pipe(fd) < 0)
  39                 return;
  40 #ifndef __MINGW32__
  41         pid = fork();
  42         if (pid < 0) {
  43                 close(fd[0]);
  44                 close(fd[1]);
  45                 return;
  46         }
  47
  48         /* return in the child */
  49         if (!pid) {
  50                 dup2(fd[1], 1);
  51                 close(fd[0]);
  52                 close(fd[1]);
  53                 return;
  54         }
  55
  56         /* The original process turns into the PAGER */
  57         dup2(fd[0], 0);
  58         close(fd[0]);
  59         close(fd[1]);
  60
  61         setenv("LESS", "FRSX", 0);
  62         run_pager(pager);
  63         die("unable to execute pager '%s'", pager);
  64         exit(255);
  65 #else
  66         /* spawn the pager */
  67         pager_argv[2] = pager;
  68         if (spawnvpe_pipe(pager_argv[0], pager_argv, environ, fd, NULL) < 0)
  69                 return;
  70
  71         /* original process continues, but writes to the pipe */
  72         dup2(fd[1], 1);
  73         close(fd[1]);
  74 #endif
  75 }