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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:46:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:46:30 +0000 |
commit | b5896ba9f6047e7031e2bdee0622d543e11a6734 (patch) | |
tree | fd7b460593a2fee1be579bec5697e6d887ea3421 /src/util/non_blocking.c | |
parent | Initial commit. (diff) | |
download | postfix-b5896ba9f6047e7031e2bdee0622d543e11a6734.tar.xz postfix-b5896ba9f6047e7031e2bdee0622d543e11a6734.zip |
Adding upstream version 3.4.23.upstream/3.4.23upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/util/non_blocking.c')
-rw-r--r-- | src/util/non_blocking.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/src/util/non_blocking.c b/src/util/non_blocking.c new file mode 100644 index 0000000..6427cd8 --- /dev/null +++ b/src/util/non_blocking.c @@ -0,0 +1,66 @@ +/*++ +/* NAME +/* non_blocking 3 +/* SUMMARY +/* set/clear non-blocking flag +/* SYNOPSIS +/* #include <iostuff.h> +/* +/* int non_blocking(int fd, int on) +/* DESCRIPTION +/* the \fInon_blocking\fR() function manipulates the non-blocking +/* flag for the specified open file, and returns the old setting. +/* +/* Arguments: +/* .IP fd +/* A file descriptor. +/* .IP on +/* For non-blocking I/O, specify a non-zero value (or use the +/* NON_BLOCKING constant); for blocking I/O, specify zero +/* (or use the BLOCKING constant). +/* +/* The result is non-zero when the non-blocking flag was enabled. +/* DIAGNOSTICS +/* All errors are fatal. +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/*--*/ + +/* System interfaces. */ + +#include "sys_defs.h" +#include <fcntl.h> + +/* Utility library. */ + +#include "msg.h" +#include "iostuff.h" + +/* Backwards compatibility */ +#ifndef O_NONBLOCK +#define PATTERN FNDELAY +#else +#define PATTERN O_NONBLOCK +#endif + +/* non_blocking - set/clear non-blocking flag */ + +int non_blocking(fd, on) +int fd; +int on; +{ + int flags; + + if ((flags = fcntl(fd, F_GETFL, 0)) < 0) + msg_fatal("fcntl: get flags: %m"); + if (fcntl(fd, F_SETFL, on ? flags | PATTERN : flags & ~PATTERN) < 0) + msg_fatal("fcntl: set non-blocking flag %s: %m", on ? "on" : "off"); + return ((flags & PATTERN) != 0); +} |