[src/trunk]: src/usr.bin/script PR/55548: Soumendra Ganguly: Since isatty(3) ...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a0201e125ce7
branches:  trunk
changeset: 936864:a0201e125ce7
user:      christos <christos%NetBSD.org@localhost>
date:      Fri Aug 07 13:36:28 2020 +0000

description:
PR/55548: Soumendra Ganguly: Since isatty(3) is implemented using
tcgetattr(3), call it directly to avoid calling it twice. This
makes error handling more precise. Also don't call err(3) when
tcsetattr(3) fails.

diffstat:

 usr.bin/script/script.c |  40 ++++++++++++++++++++++------------------
 1 files changed, 22 insertions(+), 18 deletions(-)

diffs (75 lines):

diff -r ce34eb617ea3 -r a0201e125ce7 usr.bin/script/script.c
--- a/usr.bin/script/script.c   Fri Aug 07 07:19:45 2020 +0000
+++ b/usr.bin/script/script.c   Fri Aug 07 13:36:28 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: script.c,v 1.24 2020/08/03 03:34:43 christos Exp $     */
+/*     $NetBSD: script.c,v 1.25 2020/08/07 13:36:28 christos Exp $     */
 
 /*
  * Copyright (c) 1980, 1992, 1993
@@ -39,7 +39,7 @@
 #if 0
 static char sccsid[] = "@(#)script.c   8.1 (Berkeley) 6/6/93";
 #endif
-__RCSID("$NetBSD: script.c,v 1.24 2020/08/03 03:34:43 christos Exp $");
+__RCSID("$NetBSD: script.c,v 1.25 2020/08/07 13:36:28 christos Exp $");
 #endif /* not lint */
 
 #include <sys/types.h>
@@ -156,17 +156,22 @@
        if (pflg)
                playback(fscript);
 
-       isterm = isatty(STDIN_FILENO);
-       if (isterm) {
-               if (tcgetattr(STDIN_FILENO, &tt) == -1)
-                       err(EXIT_FAILURE, "tcgetattr");
-               if (ioctl(STDIN_FILENO, TIOCGWINSZ, &win) == -1)
+       if (tcgetattr(STDIN_FILENO, &tt) == -1 ||
+           ioctl(STDIN_FILENO, TIOCGWINSZ, &win) == -1) {
+               switch (errno) {
+               case ENOTTY:
+                       if (openpty(&master, &slave, NULL, NULL, NULL) == -1)
+                               err(EXIT_FAILURE, "openpty");
+                       break;
+               case EBADF:
+                       err(EXIT_FAILURE, "%d not valid fd", STDIN_FILENO);
+               default: /* errno == EFAULT or EINVAL for ioctl. Not reached in practice. */
                        err(EXIT_FAILURE, "ioctl");
+               }
+       } else {
                if (openpty(&master, &slave, NULL, &tt, &win) == -1)
                        err(EXIT_FAILURE, "openpty");
-       } else {
-               if (openpty(&master, &slave, NULL, NULL, NULL) == -1)
-                       err(EXIT_FAILURE, "openpty");
+               isterm = 1;
        }
 
        if (!quiet)
@@ -377,18 +382,17 @@
 {
        struct termios traw;
 
-       isterm = isatty(STDOUT_FILENO);
-       if (!isterm)
+       if (tcgetattr(STDOUT_FILENO, &tt) == -1) {
+               if (errno == EBADF)
+                       err(EXIT_FAILURE, "%d not valid fd", STDOUT_FILENO);
+               /* errno == ENOTTY */
                return;
-
-       if (tcgetattr(STDOUT_FILENO, &tt) == -1)
-               err(EXIT_FAILURE, "tcgetattr");
-
+       }
+       isterm = 1;
        traw = tt;
        cfmakeraw(&traw);
        traw.c_lflag |= ISIG;
-       if (tcsetattr(STDOUT_FILENO, TCSANOW, &traw) == -1)
-               err(EXIT_FAILURE, "tcsetattr");
+        (void)tcsetattr(STDOUT_FILENO, TCSANOW, &traw);
 }
 
 static void