/* runcap - run program and capture its output
Copyright (C) 2019 Sergey Poznyakoff
Runcap is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.
Runcap is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with Runcap. If not, see . */
#include
#include
#include
#include
#include "runcap.h"
ssize_t
runcap_read(struct runcap *rc, int sd, char *buf, size_t size)
{
struct stream_capture *cap;
ssize_t nread = 0;
if (!buf) {
errno = EINVAL;
return -1;
}
if (size == 0)
return 0;
cap = runcap_get_capture(rc, sd);
if (!cap)
return -1;
while (size) {
size_t avail = cap->sc_level - cap->sc_cur;
if (avail == 0) {
if (cap->sc_storfd != -1) {
ssize_t r = read(cap->sc_storfd,
cap->sc_base,
cap->sc_size);
if (r < 0)
return -1;
else if (r == 0)
break;
avail = r;
cap->sc_level = r;
cap->sc_cur = 0;
} else {
break;
}
}
if (avail > size)
avail = size;
memcpy(buf + nread, cap->sc_base + cap->sc_cur, avail);
cap->sc_cur += avail;
nread += avail;
size -= avail;
}
return nread;
}