git-send-email: Add --thread option
[git/aroben.git] / pager.c
blob5f280ab52720772905cacbcba522ecc9c81bb529
1 #include "cache.h"
3 #include <sys/select.h>
5 /*
6 * This is split up from the rest of git so that we might do
7 * something different on Windows, for example.
8 */
10 static void run_pager(const char *pager)
13 * Work around bug in "less" by not starting it until we
14 * have real input
16 fd_set in;
18 FD_ZERO(&in);
19 FD_SET(0, &in);
20 select(1, &in, NULL, &in, NULL);
22 execlp(pager, pager, NULL);
23 execl("/bin/sh", "sh", "-c", pager, NULL);
26 void setup_pager(void)
28 pid_t pid;
29 int fd[2];
30 const char *pager = getenv("GIT_PAGER");
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;
41 pager_in_use = 1; /* means we are emitting to terminal */
43 if (pipe(fd) < 0)
44 return;
45 pid = fork();
46 if (pid < 0) {
47 close(fd[0]);
48 close(fd[1]);
49 return;
52 /* return in the child */
53 if (!pid) {
54 dup2(fd[1], 1);
55 close(fd[0]);
56 close(fd[1]);
57 return;
60 /* The original process turns into the PAGER */
61 dup2(fd[0], 0);
62 close(fd[0]);
63 close(fd[1]);
65 setenv("LESS", "FRSX", 0);
66 run_pager(pager);
67 die("unable to execute pager '%s'", pager);
68 exit(255);