Provide git_config with a callback-data parameter
[git/git.git] / pager.c
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
8 static int spawned_pager;
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 if (!pager_program)
36 git_config(git_default_config, NULL);
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
77 int 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 }