From bc6ba81cbccea13e9593300a644871cd49aa8aa2 Mon Sep 17 00:00:00 2001 From: Koichi Murase Date: Tue, 24 Aug 2021 06:25:05 +0900 Subject: fix a problem that the standard streams are unexpectedly closed In the current implementation, the slave PTY (assigned to the variable `s') is always closed after duplicating it to file descriptors of standard streams (0, 1, and 2). However, when the allocated slave PTY `s' is already one of 0, 1, or 2, this causes unexpected closing of a standard stream. The same problem occurs when the file descriptor of the master PTY (the variable `m') is one of 0, 1, or 2. In this patch, the original master PTY (m) is closed before it would be overwritten by duplicated slave PTYs. The original slave PTY (s) is closed only when it is not one of the stanrad streams. --- st.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/st.c b/st.c index 817cc47..1934bcf 100644 --- a/st.c +++ b/st.c @@ -800,14 +800,15 @@ ttynew(const char *line, char *cmd, const char *out, char **args) break; case 0: close(iofd); + close(m); setsid(); /* create a new process group */ dup2(s, 0); dup2(s, 1); dup2(s, 2); if (ioctl(s, TIOCSCTTY, NULL) < 0) die("ioctl TIOCSCTTY failed: %s\n", strerror(errno)); - close(s); - close(m); + if (s > 2) + close(s); #ifdef __OpenBSD__ if (pledge("stdio getpw proc exec", NULL) == -1) die("pledge\n"); -- cgit v1.2.3