[src/trunk]: src/lib/libutil KNF; Simplify some logic, so that lines don't wr...

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

details:   https://anonhg.NetBSD.org/src/rev/6f738ff3400d
branches:  trunk
changeset: 570047:6f738ff3400d
user:      christos <christos%NetBSD.org@localhost>
date:      Sat Sep 18 20:14:22 2004 +0000

description:
KNF; Simplify some logic, so that lines don't wrap. Explain why we
break, continue, or return from the tty scanning loops.

diffstat:

 lib/libutil/pty.c |  77 ++++++++++++++++++++++++++----------------------------
 1 files changed, 37 insertions(+), 40 deletions(-)

diffs (138 lines):

diff -r 2aa19a92c5ec -r 6f738ff3400d lib/libutil/pty.c
--- a/lib/libutil/pty.c Sat Sep 18 18:49:50 2004 +0000
+++ b/lib/libutil/pty.c Sat Sep 18 20:14:22 2004 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pty.c,v 1.24 2004/09/18 16:44:38 yamt Exp $    */
+/*     $NetBSD: pty.c,v 1.25 2004/09/18 20:14:22 christos Exp $        */
 
 /*-
  * Copyright (c) 1990, 1993, 1994
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)pty.c      8.3 (Berkeley) 5/16/94";
 #else
-__RCSID("$NetBSD: pty.c,v 1.24 2004/09/18 16:44:38 yamt Exp $");
+__RCSID("$NetBSD: pty.c,v 1.25 2004/09/18 20:14:22 christos Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -60,7 +60,7 @@
 #define TTY_NEW_SUFFIX "ghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
 
 int
-openpty(int *amaster, int *aslave, char *name, struct termios *termp, 
+openpty(int *amaster, int *aslave, char *name, struct termios *term,
        struct winsize *winp)
 {
        static char line[] = "/dev/XtyXX";
@@ -72,7 +72,7 @@
        _DIAGASSERT(amaster != NULL);
        _DIAGASSERT(aslave != NULL);
        /* name may be NULL */
-       /* termp may be NULL */
+       /* term may be NULL */
        /* winp may be NULL */
 
        if ((master = open("/dev/ptm", O_RDWR)) != -1) {
@@ -97,68 +97,65 @@
                        line[5] = 'p';
                        line[9] = *cp2;
                        if ((master = open(line, O_RDWR, 0)) == -1) {
-                               if (errno == ENOENT) {
-                                       if (cp2 - cp + 1 < sizeof(TTY_OLD_SUFFIX))
-                                               return (-1); /* out of ptys */
-                                       else
-                                               break;
-                               }
-                       } else {
-                               line[5] = 't';
-                               linep = line;
-                               if (chown(line, getuid(), ttygid) == 0 &&
-                                   chmod(line, S_IRUSR|S_IWUSR|S_IWGRP) == 0 &&
-                                   revoke(line) == 0 &&
-                                   (slave = open(line, O_RDWR, 0)) != -1) {
+                               if (errno != ENOENT)
+                                       continue;       /* busy */
+                               if (cp2 - cp + 1 < sizeof(TTY_OLD_SUFFIX))
+                                       return -1; /* out of ptys */
+                               else    
+                                       break;  /* out of ptys in this group */
+                       }
+                       line[5] = 't';
+                       linep = line;
+                       if (chown(line, getuid(), ttygid) == 0 &&
+                           chmod(line, S_IRUSR|S_IWUSR|S_IWGRP) == 0 &&
+                           revoke(line) == 0 &&
+                           (slave = open(line, O_RDWR, 0)) != -1) {
 gotit:
-                                       *amaster = master;
-                                       *aslave = slave;
-                                       if (name)
-                                               strcpy(name, linep);
-                                       if (termp)
-                                               (void) tcsetattr(slave,
-                                                       TCSAFLUSH, termp);
-                                       if (winp)
-                                               (void) ioctl(slave, TIOCSWINSZ,
-                                                   winp);
-                                       return (0);
-                               }
-                               (void) close(master);
+                               *amaster = master;
+                               *aslave = slave;
+                               if (name)
+                                       (void)strcpy(name, linep);
+                               if (term)
+                                       (void)tcsetattr(slave, TCSAFLUSH, term);
+                               if (winp)
+                                       (void)ioctl(slave, TIOCSWINSZ, winp);
+                               return 0;
                        }
+                       (void)close(master);
                }
        }
        errno = ENOENT; /* out of ptys */
-       return (-1);
+       return -1;
 }
 
 pid_t
-forkpty(int *amaster, char *name, struct termios *termp, struct winsize *winp)
+forkpty(int *amaster, char *name, struct termios *term, struct winsize *winp)
 {
        int master, slave;
        pid_t pid;
 
        _DIAGASSERT(amaster != NULL);
        /* name may be NULL */
-       /* termp may be NULL */
+       /* term may be NULL */
        /* winp may be NULL */
 
-       if (openpty(&master, &slave, name, termp, winp) == -1)
-               return (-1);
+       if (openpty(&master, &slave, name, term, winp) == -1)
+               return -1;
        switch (pid = fork()) {
        case -1:
-               return (-1);
+               return -1;
        case 0:
                /*
                 * child
                 */
-               (void) close(master);
+               (void)close(master);
                login_tty(slave);
-               return (0);
+               return 0;
        }
        /*
         * parent
         */
        *amaster = master;
-       (void) close(slave);
-       return (pid);
+       (void)close(slave);
+       return pid;
 }