git-am: initialize variable $resume on startup
[git/git.git] / pager.c
CommitLineData
f67b45f8
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1#include "cache.h"
2
35ce8622
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3#include <sys/select.h>
4
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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
402461aa 10static void run_pager(const char *pager)
f67b45f8 11{
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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
402461aa 22 execlp(pager, pager, NULL);
34fd1c9a 23 execl("/bin/sh", "sh", "-c", pager, NULL);
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24}
25
26void setup_pager(void)
27{
28 pid_t pid;
29 int fd[2];
c27d205a 30 const char *pager = getenv("GIT_PAGER");
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31
32 if (!isatty(1))
33 return;
54adf370
BG
34 if (!pager)
35 pager = pager_program;
c27d205a
ML
36 if (!pager)
37 pager = getenv("PAGER");
402461aa
JS
38 if (!pager)
39 pager = "less";
caef71a5 40 else if (!*pager || !strcmp(pager, "cat"))
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41 return;
42
85fb65ed
JH
43 pager_in_use = 1; /* means we are emitting to terminal */
44
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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
0abc0260 67 setenv("LESS", "FRSX", 0);
402461aa 68 run_pager(pager);
34fd1c9a 69 die("unable to execute pager '%s'", pager);
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70 exit(255);
71}