t0021: use $SHELL_PATH for the filter script
[git/git.git] / pager.c
CommitLineData
f67b45f8 1#include "cache.h"
ea27a18c 2#include "run-command.h"
a3da8821 3#include "sigchain.h"
f67b45f8 4
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5#ifndef DEFAULT_PAGER
6#define DEFAULT_PAGER "less"
7#endif
8
f67b45f8 9/*
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10 * This is split up from the rest of git so that we can do
11 * something different on Windows.
f67b45f8
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12 */
13
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14static int spawned_pager;
15
71064e3f 16#ifndef WIN32
ea27a18c 17static void pager_preexec(void)
f67b45f8 18{
35ce8622
LT
19 /*
20 * Work around bug in "less" by not starting it until we
21 * have real input
22 */
23 fd_set in;
24
25 FD_ZERO(&in);
26 FD_SET(0, &in);
27 select(1, &in, NULL, &in, NULL);
f67b45f8 28}
ea27a18c 29#endif
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30
31static const char *pager_argv[] = { "sh", "-c", NULL, NULL };
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32static struct child_process pager_process;
33
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34static void wait_for_pager(void)
35{
36 fflush(stdout);
37 fflush(stderr);
38 /* signal EOF to pager */
39 close(1);
40 close(2);
41 finish_command(&pager_process);
42}
f67b45f8 43
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44static void wait_for_pager_signal(int signo)
45{
46 wait_for_pager();
47 sigchain_pop(signo);
48 raise(signo);
49}
50
63618245 51const char *git_pager(void)
f67b45f8 52{
63618245 53 const char *pager;
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54
55 if (!isatty(1))
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56 return NULL;
57
58 pager = getenv("GIT_PAGER");
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59 if (!pager) {
60 if (!pager_program)
ef90d6d4 61 git_config(git_default_config, NULL);
54adf370 62 pager = pager_program;
cad3a205 63 }
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64 if (!pager)
65 pager = getenv("PAGER");
402461aa 66 if (!pager)
a3d023d0 67 pager = DEFAULT_PAGER;
caef71a5 68 else if (!*pager || !strcmp(pager, "cat"))
63618245
JN
69 pager = NULL;
70
71 return pager;
72}
73
74void setup_pager(void)
75{
76 const char *pager = git_pager();
77
78 if (!pager)
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79 return;
80
6e9af863 81 spawned_pager = 1; /* means we are emitting to terminal */
85fb65ed 82
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83 /* spawn the pager */
84 pager_argv[2] = pager;
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85 pager_process.argv = pager_argv;
86 pager_process.in = -1;
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87 if (!getenv("LESS")) {
88 static const char *env[] = { "LESS=FRSX", NULL };
89 pager_process.env = env;
90 }
71064e3f 91#ifndef WIN32
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92 pager_process.preexec_cb = pager_preexec;
93#endif
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94 if (start_command(&pager_process))
95 return;
96
97 /* original process continues, but writes to the pipe */
98 dup2(pager_process.in, 1);
a8335024
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99 if (isatty(2))
100 dup2(pager_process.in, 2);
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101 close(pager_process.in);
102
103 /* this makes sure that the parent terminates after the pager */
a3da8821 104 sigchain_push_common(wait_for_pager_signal);
bfdd9ffd 105 atexit(wait_for_pager);
f67b45f8 106}
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107
108int pager_in_use(void)
109{
110 const char *env;
111
112 if (spawned_pager)
113 return 1;
114
115 env = getenv("GIT_PAGER_IN_USE");
116 return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
117}