Commit | Line | Data |
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2f4ce5ec JP |
1 | #include <sys/select.h> |
2 | #include <stdlib.h> | |
3 | #include <stdio.h> | |
4 | #include <string.h> | |
5 | #include <signal.h> | |
6 | #include "pager.h" | |
a930d2c0 IM |
7 | #include "run-command.h" |
8 | #include "sigchain.h" | |
096d3558 | 9 | #include "subcmd-config.h" |
a930d2c0 IM |
10 | |
11 | /* | |
12 | * This is split up from the rest of git so that we can do | |
13 | * something different on Windows. | |
14 | */ | |
15 | ||
16 | static int spawned_pager; | |
17 | ||
096d3558 JP |
18 | void pager_init(const char *pager_env) |
19 | { | |
20 | subcmd_config.pager_env = pager_env; | |
21 | } | |
22 | ||
a930d2c0 IM |
23 | static void pager_preexec(void) |
24 | { | |
25 | /* | |
26 | * Work around bug in "less" by not starting it until we | |
27 | * have real input | |
28 | */ | |
29 | fd_set in; | |
30 | ||
31 | FD_ZERO(&in); | |
32 | FD_SET(0, &in); | |
33 | select(1, &in, NULL, &in, NULL); | |
34 | ||
35 | setenv("LESS", "FRSX", 0); | |
36 | } | |
a930d2c0 IM |
37 | |
38 | static const char *pager_argv[] = { "sh", "-c", NULL, NULL }; | |
39 | static struct child_process pager_process; | |
40 | ||
41 | static void wait_for_pager(void) | |
42 | { | |
43 | fflush(stdout); | |
44 | fflush(stderr); | |
45 | /* signal EOF to pager */ | |
46 | close(1); | |
47 | close(2); | |
48 | finish_command(&pager_process); | |
49 | } | |
50 | ||
51 | static void wait_for_pager_signal(int signo) | |
52 | { | |
53 | wait_for_pager(); | |
54 | sigchain_pop(signo); | |
55 | raise(signo); | |
56 | } | |
57 | ||
58 | void setup_pager(void) | |
59 | { | |
096d3558 | 60 | const char *pager = getenv(subcmd_config.pager_env); |
a930d2c0 IM |
61 | |
62 | if (!isatty(1)) | |
63 | return; | |
a930d2c0 IM |
64 | if (!pager) |
65 | pager = getenv("PAGER"); | |
21cfc5e1 ML |
66 | if (!(pager || access("/usr/bin/pager", X_OK))) |
67 | pager = "/usr/bin/pager"; | |
68 | if (!(pager || access("/usr/bin/less", X_OK))) | |
69 | pager = "/usr/bin/less"; | |
a930d2c0 | 70 | if (!pager) |
21cfc5e1 ML |
71 | pager = "cat"; |
72 | if (!*pager || !strcmp(pager, "cat")) | |
a930d2c0 IM |
73 | return; |
74 | ||
75 | spawned_pager = 1; /* means we are emitting to terminal */ | |
76 | ||
77 | /* spawn the pager */ | |
78 | pager_argv[2] = pager; | |
79 | pager_process.argv = pager_argv; | |
80 | pager_process.in = -1; | |
a930d2c0 | 81 | pager_process.preexec_cb = pager_preexec; |
fde953c1 | 82 | |
a930d2c0 IM |
83 | if (start_command(&pager_process)) |
84 | return; | |
85 | ||
86 | /* original process continues, but writes to the pipe */ | |
87 | dup2(pager_process.in, 1); | |
88 | if (isatty(2)) | |
89 | dup2(pager_process.in, 2); | |
90 | close(pager_process.in); | |
91 | ||
92 | /* this makes sure that the parent terminates after the pager */ | |
93 | sigchain_push_common(wait_for_pager_signal); | |
94 | atexit(wait_for_pager); | |
95 | } | |
96 | ||
97 | int pager_in_use(void) | |
98 | { | |
a871a775 | 99 | return spawned_pager; |
a930d2c0 | 100 | } |