src/lib/libc/gen/popen.c, branch release/4.2.0_cvs

This commit was manufactured by cvs2svn to create tag

2000-11-20T04:41:45+00:00

'RELENG_4_2_0_RELEASE'.

This commit was manufactured to restore the state of the 4.2-RELEASE image.
Releases prior to 5.3-RELEASE are omitting the secure/ and crypto/ subdirs.

Simplify sytem call renaming. Instead of _foo() <-- _libc_foo <-- foo(),

2000-01-27T23:07:25+00:00

just use _foo() <-- foo().  In the case of a libpthread that doesn't do
call conversion (such as linuxthreads and our upcoming libpthread), this
is adequate.  In the case of libc_r, we still need three names, which are
now _thread_sys_foo() <-- _foo() <-- foo().

Convert all internal libc usage of: aio_suspend(), close(), fsync(), msync(),
nanosleep(), open(), fcntl(), read(), and write() to _foo() instead of foo().

Remove all internal libc usage of: creat(), pause(), sleep(), system(),
tcdrain(), wait(), and waitpid().

Make thread cancellation fully POSIX-compliant.

Suggested by:	deischen

Add three-tier symbol naming in support of POSIX thread cancellation

2000-01-12T09:23:48+00:00

points.  For library functions, the pattern is __sleep() <--
_libc_sleep() <-- sleep().  The arrows represent weak aliases.  For
system calls, the pattern is _read() <-- _libc_read() <-- read().

Conform to POSIX and close any copies of popen() descriptors inherited by a

1998-10-15T01:47:40+00:00

popen()ed child.

PR:		misc/7810
Submitted by:	Wayne Scott

Avoid the need for calling functions that malloc after a vfork().

1998-10-11T14:11:51+00:00

vfork -> fork. The child calls execl() which calls malloc(), so

1998-10-10T19:30:45+00:00

vfork() can't be used.  We could use alloca() in execl() so that
it can be called between vfork() and execve(), but a "portable"
popen() shouldn't depend on this.  Calling execle() instead of
execl() should be fairly safe, since execle() is supposed to be
callable from signal handlers and signal handlers can't call
malloc().  However, execle() is broken.

FIxed the cleanup. I forgot to leave stdin alone in the usual (!twoway)

1997-04-22T09:44:06+00:00

case.

Clean-up my modification of popen.c for vfork. Bruce's (this) is better.

1997-04-20T20:17:04+00:00

Submitted by:	Bruce Evans

Fix the problem in popen that makes correct vfork semantics fail.

1997-04-16T03:26:50+00:00

Specifically, popen modifies a variable "pdes[1]" in the child
in such a way that it breaks code in the parent (due to the address
space sharing.)

Fixed cleaning up after malloc failure, which was broken by Lite2.

1997-03-11T18:51:43+00:00

We don't use socketpair(), so don't #include .

Restored some gcc-quieting parentheses that were lost in the Lite2 merge.