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-rw-r--r--src/util/write_buf.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/src/util/write_buf.c b/src/util/write_buf.c
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+++ b/src/util/write_buf.c
@@ -0,0 +1,89 @@
+/*++
+/* NAME
+/* write_buf 3
+/* SUMMARY
+/* write buffer or bust
+/* SYNOPSIS
+/* #include <iostuff.h>
+/*
+/* ssize_t write_buf(fd, buf, len, timeout)
+/* int fd;
+/* const char *buf;
+/* ssize_t len;
+/* int timeout;
+/* DESCRIPTION
+/* write_buf() writes a buffer to the named stream in as many
+/* fragments as needed, and returns the number of bytes written,
+/* which is always the number requested or an error indication.
+/*
+/* Arguments:
+/* .IP fd
+/* File descriptor in the range 0..FD_SETSIZE.
+/* .IP buf
+/* Address of data to be written.
+/* .IP len
+/* Amount of data to be written.
+/* .IP timeout
+/* Bounds the time in seconds to wait until \fIfd\fD becomes writable.
+/* A value <= 0 means do not wait; this is useful only when \fIfd\fR
+/* uses blocking I/O.
+/* DIAGNOSTICS
+/* write_buf() returns -1 in case of trouble. The global \fIerrno\fR
+/* variable reflects the nature of the problem.
+/* 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 library. */
+
+#include <sys_defs.h>
+#include <unistd.h>
+#include <errno.h>
+#include <time.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <iostuff.h>
+
+/* write_buf - write buffer or bust */
+
+ssize_t write_buf(int fd, const char *buf, ssize_t len, int timeout)
+{
+ const char *start = buf;
+ ssize_t count;
+ time_t expire;
+ int time_left = timeout;
+
+ if (time_left > 0)
+ expire = time((time_t *) 0) + time_left;
+
+ while (len > 0) {
+ if (time_left > 0 && write_wait(fd, time_left) < 0)
+ return (-1);
+ if ((count = write(fd, buf, len)) < 0) {
+ if ((errno == EAGAIN && time_left > 0) || errno == EINTR)
+ /* void */ ;
+ else
+ return (-1);
+ } else {
+ buf += count;
+ len -= count;
+ }
+ if (len > 0 && time_left > 0) {
+ time_left = expire - time((time_t *) 0);
+ if (time_left <= 0) {
+ errno = ETIMEDOUT;
+ return (-1);
+ }
+ }
+ }
+ return (buf - start);
+}