/*++ /* 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); }