blob: 3322b8446e891af7d420f0eb18e2232db51e8621 [file] [log] [blame]
Ingo Molnara930d2c2009-05-27 09:50:13 +02001#include "cache.h"
2#include "run-command.h"
3#include "sigchain.h"
4
5/*
6 * This is split up from the rest of git so that we can do
7 * something different on Windows.
8 */
9
10static int spawned_pager;
11
Ingo Molnara930d2c2009-05-27 09:50:13 +020012static void pager_preexec(void)
13{
14 /*
15 * Work around bug in "less" by not starting it until we
16 * have real input
17 */
18 fd_set in;
19
20 FD_ZERO(&in);
21 FD_SET(0, &in);
22 select(1, &in, NULL, &in, NULL);
23
24 setenv("LESS", "FRSX", 0);
25}
Ingo Molnara930d2c2009-05-27 09:50:13 +020026
27static const char *pager_argv[] = { "sh", "-c", NULL, NULL };
28static struct child_process pager_process;
29
30static void wait_for_pager(void)
31{
32 fflush(stdout);
33 fflush(stderr);
34 /* signal EOF to pager */
35 close(1);
36 close(2);
37 finish_command(&pager_process);
38}
39
40static void wait_for_pager_signal(int signo)
41{
42 wait_for_pager();
43 sigchain_pop(signo);
44 raise(signo);
45}
46
47void setup_pager(void)
48{
49 const char *pager = getenv("PERF_PAGER");
50
51 if (!isatty(1))
52 return;
53 if (!pager) {
54 if (!pager_program)
55 perf_config(perf_default_config, NULL);
56 pager = pager_program;
57 }
58 if (!pager)
59 pager = getenv("PAGER");
Avik Silea1b3eb2012-05-29 16:05:25 +053060 if (!pager) {
61 if (!access("/usr/bin/pager", X_OK))
62 pager = "/usr/bin/pager";
63 }
Ingo Molnara930d2c2009-05-27 09:50:13 +020064 if (!pager)
65 pager = "less";
66 else if (!*pager || !strcmp(pager, "cat"))
67 return;
68
69 spawned_pager = 1; /* means we are emitting to terminal */
70
71 /* spawn the pager */
72 pager_argv[2] = pager;
73 pager_process.argv = pager_argv;
74 pager_process.in = -1;
Ingo Molnara930d2c2009-05-27 09:50:13 +020075 pager_process.preexec_cb = pager_preexec;
Ingo Molnarfde953c2009-06-27 06:06:39 +020076
Ingo Molnara930d2c2009-05-27 09:50:13 +020077 if (start_command(&pager_process))
78 return;
79
80 /* original process continues, but writes to the pipe */
81 dup2(pager_process.in, 1);
82 if (isatty(2))
83 dup2(pager_process.in, 2);
84 close(pager_process.in);
85
86 /* this makes sure that the parent terminates after the pager */
87 sigchain_push_common(wait_for_pager_signal);
88 atexit(wait_for_pager);
89}
90
91int pager_in_use(void)
92{
93 const char *env;
94
95 if (spawned_pager)
96 return 1;
97
98 env = getenv("PERF_PAGER_IN_USE");
99 return env ? perf_config_bool("PERF_PAGER_IN_USE", env) : 0;
100}