refactor "dumb" terminal determination
[git/git.git] / sideband.c
1 #include "cache.h"
2 #include "pkt-line.h"
3 #include "sideband.h"
4
5 /*
6 * Receive multiplexed output stream over git native protocol.
7 * in_stream is the input stream from the remote, which carries data
8 * in pkt_line format with band designator. Demultiplex it into out
9 * and err and return error appropriately. Band #1 carries the
10 * primary payload. Things coming over band #2 is not necessarily
11 * error; they are usually informative message on the standard error
12 * stream, aka "verbose"). A message over band #3 is a signal that
13 * the remote died unexpectedly. A flush() concludes the stream.
14 */
15
16 #define PREFIX "remote: "
17
18 #define ANSI_SUFFIX "\033[K"
19 #define DUMB_SUFFIX " "
20
21 int recv_sideband(const char *me, int in_stream, int out)
22 {
23 const char *suffix;
24 char buf[LARGE_PACKET_MAX + 1];
25 struct strbuf outbuf = STRBUF_INIT;
26 int retval = 0;
27
28 if (isatty(2) && !is_terminal_dumb())
29 suffix = ANSI_SUFFIX;
30 else
31 suffix = DUMB_SUFFIX;
32
33 while (!retval) {
34 const char *b, *brk;
35 int band, len;
36 len = packet_read(in_stream, NULL, NULL, buf, LARGE_PACKET_MAX, 0);
37 if (len == 0)
38 break;
39 if (len < 1) {
40 strbuf_addf(&outbuf,
41 "%s%s: protocol error: no band designator",
42 outbuf.len ? "\n" : "", me);
43 retval = SIDEBAND_PROTOCOL_ERROR;
44 break;
45 }
46 band = buf[0] & 0xff;
47 buf[len] = '\0';
48 len--;
49 switch (band) {
50 case 3:
51 strbuf_addf(&outbuf, "%s%s%s", outbuf.len ? "\n" : "",
52 PREFIX, buf + 1);
53 retval = SIDEBAND_REMOTE_ERROR;
54 break;
55 case 2:
56 b = buf + 1;
57
58 /*
59 * Append a suffix to each nonempty line to clear the
60 * end of the screen line.
61 *
62 * The output is accumulated in a buffer and
63 * each line is printed to stderr using
64 * write(2) to ensure inter-process atomicity.
65 */
66 while ((brk = strpbrk(b, "\n\r"))) {
67 int linelen = brk - b;
68
69 if (!outbuf.len)
70 strbuf_addstr(&outbuf, PREFIX);
71 if (linelen > 0) {
72 strbuf_addf(&outbuf, "%.*s%s%c",
73 linelen, b, suffix, *brk);
74 } else {
75 strbuf_addch(&outbuf, *brk);
76 }
77 xwrite(2, outbuf.buf, outbuf.len);
78 strbuf_reset(&outbuf);
79
80 b = brk + 1;
81 }
82
83 if (*b)
84 strbuf_addf(&outbuf, "%s%s",
85 outbuf.len ? "" : PREFIX, b);
86 break;
87 case 1:
88 write_or_die(out, buf + 1, len);
89 break;
90 default:
91 strbuf_addf(&outbuf, "%s%s: protocol error: bad band #%d",
92 outbuf.len ? "\n" : "", me, band);
93 retval = SIDEBAND_PROTOCOL_ERROR;
94 break;
95 }
96 }
97
98 if (outbuf.len) {
99 strbuf_addch(&outbuf, '\n');
100 xwrite(2, outbuf.buf, outbuf.len);
101 }
102 strbuf_release(&outbuf);
103 return retval;
104 }
105
106 /*
107 * fd is connected to the remote side; send the sideband data
108 * over multiplexed packet stream.
109 */
110 void send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max)
111 {
112 const char *p = data;
113
114 while (sz) {
115 unsigned n;
116 char hdr[5];
117
118 n = sz;
119 if (packet_max - 5 < n)
120 n = packet_max - 5;
121 if (0 <= band) {
122 xsnprintf(hdr, sizeof(hdr), "%04x", n + 5);
123 hdr[4] = band;
124 write_or_die(fd, hdr, 5);
125 } else {
126 xsnprintf(hdr, sizeof(hdr), "%04x", n + 4);
127 write_or_die(fd, hdr, 4);
128 }
129 write_or_die(fd, p, n);
130 p += n;
131 sz -= n;
132 }
133 }