git/sideband.c
Michael Naumov 38de156a05 sideband.c: do not use ANSI control sequence on non-terminal
Diagnostic messages received on the sideband #2 from the server side
are sent to the standard error with ANSI terminal control sequence
"\033[K" that erases to the end of line appended at the end of each
line.

However, some programs (e.g. GitExtensions for Windows) read and
interpret and/or show the message without understanding the terminal
control sequences, resulting them to be shown to their end users.
To help these programs, squelch the control sequence when the
standard error stream is not being sent to a tty.

NOTE: I considered to cover the case that a pager has already been
started. But decided that is probably not worth worrying about here,
though, as we shouldn't be using a pager for commands that do network
communications (and if we do, omitting the magic line-clearing signal
is probably a sane thing to do).

Thanks-to: Erik Faye-Lund <kusmabite@gmail.com>
Thanks-to: Jeff King <peff@peff.net>
Signed-off-by: Michael Naumov <mnaoumov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-02 11:02:27 -07:00

153 lines
3.4 KiB
C

#include "cache.h"
#include "pkt-line.h"
#include "sideband.h"
/*
* Receive multiplexed output stream over git native protocol.
* in_stream is the input stream from the remote, which carries data
* in pkt_line format with band designator. Demultiplex it into out
* and err and return error appropriately. Band #1 carries the
* primary payload. Things coming over band #2 is not necessarily
* error; they are usually informative message on the standard error
* stream, aka "verbose"). A message over band #3 is a signal that
* the remote died unexpectedly. A flush() concludes the stream.
*/
#define PREFIX "remote:"
#define ANSI_SUFFIX "\033[K"
#define DUMB_SUFFIX " "
#define FIX_SIZE 10 /* large enough for any of the above */
int recv_sideband(const char *me, int in_stream, int out)
{
unsigned pf = strlen(PREFIX);
unsigned sf;
char buf[LARGE_PACKET_MAX + 2*FIX_SIZE];
char *suffix, *term;
int skip_pf = 0;
memcpy(buf, PREFIX, pf);
term = getenv("TERM");
if (isatty(2) && term && strcmp(term, "dumb"))
suffix = ANSI_SUFFIX;
else
suffix = DUMB_SUFFIX;
sf = strlen(suffix);
while (1) {
int band, len;
len = packet_read(in_stream, NULL, NULL, buf + pf, LARGE_PACKET_MAX, 0);
if (len == 0)
break;
if (len < 1) {
fprintf(stderr, "%s: protocol error: no band designator\n", me);
return SIDEBAND_PROTOCOL_ERROR;
}
band = buf[pf] & 0xff;
len--;
switch (band) {
case 3:
buf[pf] = ' ';
buf[pf+1+len] = '\0';
fprintf(stderr, "%s\n", buf);
return SIDEBAND_REMOTE_ERROR;
case 2:
buf[pf] = ' ';
do {
char *b = buf;
int brk = 0;
/*
* If the last buffer didn't end with a line
* break then we should not print a prefix
* this time around.
*/
if (skip_pf) {
b += pf+1;
} else {
len += pf+1;
brk += pf+1;
}
/* Look for a line break. */
for (;;) {
brk++;
if (brk > len) {
brk = 0;
break;
}
if (b[brk-1] == '\n' ||
b[brk-1] == '\r')
break;
}
/*
* Let's insert a suffix to clear the end
* of the screen line if a line break was
* found. Also, if we don't skip the
* prefix, then a non-empty string must be
* present too.
*/
if (brk > (skip_pf ? 0 : (pf+1 + 1))) {
char save[FIX_SIZE];
memcpy(save, b + brk, sf);
b[brk + sf - 1] = b[brk - 1];
memcpy(b + brk - 1, suffix, sf);
fprintf(stderr, "%.*s", brk + sf, b);
memcpy(b + brk, save, sf);
len -= brk;
} else {
int l = brk ? brk : len;
fprintf(stderr, "%.*s", l, b);
len -= l;
}
skip_pf = !brk;
memmove(buf + pf+1, b + brk, len);
} while (len);
continue;
case 1:
write_or_die(out, buf + pf+1, len);
continue;
default:
fprintf(stderr, "%s: protocol error: bad band #%d\n",
me, band);
return SIDEBAND_PROTOCOL_ERROR;
}
}
return 0;
}
/*
* fd is connected to the remote side; send the sideband data
* over multiplexed packet stream.
*/
ssize_t send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max)
{
ssize_t ssz = sz;
const char *p = data;
while (sz) {
unsigned n;
char hdr[5];
n = sz;
if (packet_max - 5 < n)
n = packet_max - 5;
if (0 <= band) {
sprintf(hdr, "%04x", n + 5);
hdr[4] = band;
write_or_die(fd, hdr, 5);
} else {
sprintf(hdr, "%04x", n + 4);
write_or_die(fd, hdr, 4);
}
write_or_die(fd, p, n);
p += n;
sz -= n;
}
return ssz;
}