diff options
Diffstat (limited to 'usr.bin/tail/forward.c')
| -rw-r--r-- | usr.bin/tail/forward.c | 73 |
1 files changed, 51 insertions, 22 deletions
diff --git a/usr.bin/tail/forward.c b/usr.bin/tail/forward.c index 31f5ea6..80cd185 100644 --- a/usr.bin/tail/forward.c +++ b/usr.bin/tail/forward.c @@ -32,6 +32,8 @@ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. + * + * $FreeBSD$ */ #ifndef lint @@ -43,6 +45,7 @@ static char sccsid[] = "@(#)forward.c 8.1 (Berkeley) 6/6/93"; #include <sys/time.h> #include <sys/mman.h> +#include <event.h> #include <limits.h> #include <fcntl.h> #include <errno.h> @@ -84,9 +87,8 @@ forward(fp, style, off, sbp) long off; struct stat *sbp; { - register int ch; - struct timeval interval; - struct stat sb2; + int ch, add_events = 0, kq = -1; + struct kevent ev[2]; switch(style) { case FBYTES: @@ -161,10 +163,12 @@ forward(fp, style, off, sbp) break; } - /* - * We pause for 1/4 second after displaying any data that has - * accumulated since we read the file. - */ + if (fflag) { + kq = kqueue(); + if (kq < 0) + err(1, "kqueue"); + add_events = 1; + } for (;;) { while ((ch = getc(fp)) != EOF) @@ -175,24 +179,49 @@ forward(fp, style, off, sbp) return; } (void)fflush(stdout); - if (!fflag) + if (! fflag) break; - - (void) usleep(250000); clearerr(fp); - if (Fflag && fileno(fp) != STDIN_FILENO && - stat(fname, &sb2) != -1) { - if (sb2.st_ino != sbp->st_ino || - sb2.st_dev != sbp->st_dev || - sb2.st_rdev != sbp->st_rdev || - sb2.st_nlink == 0) { - fp = freopen(fname, "r", fp); - if (fp == NULL) { - ierr(); - break; - } - *sbp = sb2; + if (add_events) { + int n = 0; + struct kevent *evp[2]; + struct timespec ts = { 0, 0 }; + + if (Fflag && fileno(fp) != STDIN_FILENO) { + ev[n].ident = fileno(fp); + ev[n].filter = EVFILT_VNODE; + ev[n].flags = EV_ADD | EV_ENABLE | EV_CLEAR; + ev[n].fflags = NOTE_DELETE | NOTE_RENAME; + evp[n] = &ev[n]; + n++; + } + ev[n].ident = fileno(fp); + ev[n].filter = EVFILT_READ; + ev[n].flags = EV_ADD | EV_ENABLE; + evp[n] = &ev[n]; + n++; + + if (kevent(kq, n, evp, 0, NULL, &ts) < 0) + err(1, "kevent"); + add_events = 0; + } + + if (kevent(kq, 0, NULL, 1, ev, NULL) < 0) + err(1, "kevent"); + + if (ev->filter == EVFILT_VNODE) { + fp = freopen(fname, "r", fp); + if (fp == NULL) { + ierr(); + break; + } + add_events = 1; + } else if (ev->data < 0) { + /* file shrank, reposition to end */ + if (fseek(fp, 0L, SEEK_END) == -1) { + ierr(); + return; } } } |
