Fix bin/164947: tee looses data when writing to non-blocking file descriptors

tee was not handling EAGAIN

patch submitted by Diomidis Spinellis <dds@aueb.gr>. Thanks so much

reproduced and re-tested locally
This commit is contained in:
Martin Cracauer 2012-02-10 22:16:17 +00:00
parent e1976efd69
commit 2477c8ab78
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=231449

View file

@ -42,8 +42,10 @@ static const char rcsid[] =
#endif /* not lint */
#include <sys/types.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
@ -60,6 +62,7 @@ static LIST *head;
static void add(int, const char *);
static void usage(void);
static void waitfor(int fd);
int
main(int argc, char *argv[])
@ -106,9 +109,14 @@ main(int argc, char *argv[])
bp = buf;
do {
if ((wval = write(p->fd, bp, n)) == -1) {
warn("%s", p->name);
exitval = 1;
break;
if (errno == EAGAIN) {
waitfor(p->fd);
wval = 0;
} else {
warn("%s", p->name);
exitval = 1;
break;
}
}
bp += wval;
} while (n -= wval);
@ -137,3 +145,15 @@ add(int fd, const char *name)
p->next = head;
head = p;
}
/* Wait for the specified fd to be ready for writing */
static void
waitfor(int fd)
{
fd_set writefds;
FD_ZERO(&writefds);
FD_SET(fd, &writefds);
if (select(fd + 1, NULL, &writefds, NULL, NULL) == -1)
err(1, "select");
}