don't write openpty results until success is determined

not only is this semantically more correct; it also reduces code size
slightly by eliminating the need for the compiler to assume the
possibility of aliasing.
This commit is contained in:
Rich Felker 2014-12-20 23:22:57 -05:00
parent 4b2cb37770
commit 3b26a32df4
1 changed files with 12 additions and 10 deletions

View File

@ -6,28 +6,30 @@
/* Nonstandard, but vastly superior to the standard functions */
int openpty(int *m, int *s, char *name, const struct termios *tio, const struct winsize *ws)
int openpty(int *pm, int *ps, char *name, const struct termios *tio, const struct winsize *ws)
{
int n=0;
int m, s, n=0;
char buf[20];
*m = open("/dev/ptmx", O_RDWR|O_NOCTTY);
if (*m < 0) return -1;
m = open("/dev/ptmx", O_RDWR|O_NOCTTY);
if (m < 0) return -1;
if (ioctl(*m, TIOCSPTLCK, &n) || ioctl (*m, TIOCGPTN, &n)) {
close(*m);
if (ioctl(m, TIOCSPTLCK, &n) || ioctl (m, TIOCGPTN, &n)) {
close(m);
return -1;
}
if (!name) name = buf;
snprintf(name, sizeof buf, "/dev/pts/%d", n);
if ((*s = open(name, O_RDWR|O_NOCTTY)) < 0) {
close(*m);
if ((s = open(name, O_RDWR|O_NOCTTY)) < 0) {
close(m);
return -1;
}
if (tio) tcsetattr(*s, TCSANOW, tio);
if (ws) ioctl(*s, TIOCSWINSZ, ws);
if (tio) tcsetattr(s, TCSANOW, tio);
if (ws) ioctl(s, TIOCSWINSZ, ws);
*pm = m;
*ps = s;
return 0;
}