Add support for following more than one file i.e.
tail -f file1 file2
This commit is contained in:
Paul Richards
parent
dba13dd1d3
commit
15a55f7926
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=137225
@ -50,8 +50,17 @@ struct mapinfo {
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int fd;
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};
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struct file_info {
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FILE *fp;
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char *file_name;
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struct stat st;
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};
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typedef struct file_info file_info_t;
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enum STYLE { NOTSET = 0, FBYTES, FLINES, RBYTES, RLINES, REVERSE };
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void follow(file_info_t *, enum STYLE, off_t);
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void forward(FILE *, enum STYLE, off_t, struct stat *);
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void reverse(FILE *, enum STYLE, off_t, struct stat *);
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@ -63,5 +72,5 @@ void oerr(void);
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int mapprint(struct mapinfo *, off_t, off_t);
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int maparound(struct mapinfo *, off_t);
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extern int Fflag, fflag, rflag, rval;
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extern int Fflag, fflag, rflag, rval, no_files;
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extern const char *fname;
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@ -66,6 +66,10 @@ static void rlines(FILE *, off_t, struct stat *);
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#define USE_KQUEUE 1
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#define ADD_EVENTS 2
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struct kevent *ev;
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int action = USE_SLEEP;
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int kq;
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/*
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* forward -- display the file, from an offset, forward.
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*
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@ -172,95 +176,14 @@ forward(FILE *fp, enum STYLE style, off_t off, struct stat *sbp)
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break;
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}
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if (fflag) {
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kq = kqueue();
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if (kq < 0)
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err(1, "kqueue");
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action = ADD_EVENTS;
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}
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for (;;) {
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while ((ch = getc(fp)) != EOF)
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if (putchar(ch) == EOF)
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oerr();
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if (ferror(fp)) {
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ierr();
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return;
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}
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(void)fflush(stdout);
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if (! fflag)
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break;
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clearerr(fp);
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switch (action) {
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case ADD_EVENTS:
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n = 0;
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ts.tv_sec = 0;
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ts.tv_nsec = 0;
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if (Fflag && fileno(fp) != STDIN_FILENO) {
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EV_SET(&ev[n], fileno(fp), EVFILT_VNODE,
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EV_ADD | EV_ENABLE | EV_CLEAR,
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NOTE_DELETE | NOTE_RENAME, 0, 0);
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n++;
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}
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EV_SET(&ev[n], fileno(fp), EVFILT_READ,
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EV_ADD | EV_ENABLE | EV_CLEAR, 0, 0, 0);
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n++;
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if (kevent(kq, ev, n, NULL, 0, &ts) < 0) {
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action = USE_SLEEP;
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} else {
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action = USE_KQUEUE;
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}
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break;
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case USE_KQUEUE:
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ts.tv_sec = 1;
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ts.tv_nsec = 0;
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/*
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* In the -F case we set a timeout to ensure that
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* we re-stat the file at least once every second.
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*/
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n = kevent(kq, NULL, 0, ev, 1, Fflag ? &ts : NULL);
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if (n < 0)
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err(1, "kevent");
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if (n == 0) {
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/* timeout */
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break;
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} else if (ev->filter == EVFILT_READ && ev->data < 0) {
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/* file shrank, reposition to end */
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if (fseeko(fp, (off_t)0, SEEK_END) == -1) {
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ierr();
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return;
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}
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}
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break;
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case USE_SLEEP:
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(void) usleep(250000);
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clearerr(fp);
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break;
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}
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if (Fflag && fileno(fp) != STDIN_FILENO) {
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while (stat(fname, &sb2) != 0)
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/* file was rotated, wait until it reappears */
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(void)sleep(1);
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if (sb2.st_ino != sbp->st_ino ||
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sb2.st_dev != sbp->st_dev ||
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sb2.st_nlink == 0) {
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fp = freopen(fname, "r", fp);
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if (fp == NULL) {
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ierr();
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return;
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} else {
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*sbp = sb2;
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action = ADD_EVENTS;
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}
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}
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}
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while ((ch = getc(fp)) != EOF)
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if (putchar(ch) == EOF)
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oerr();
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if (ferror(fp)) {
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ierr();
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return;
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}
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(void)fflush(stdout);
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}
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/*
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@ -316,3 +239,152 @@ rlines(fp, off, sbp)
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return;
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}
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}
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/*
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* follow -- display the file, from an offset, forward.
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*
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*/
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void
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show(file_info_t *file)
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{
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int ch, first;
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first = 1;
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while ((ch = getc(file->fp)) != EOF) {
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if (first && no_files > 1) {
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(void)printf("\n==> %s <==\n", file->file_name);
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first = 0;
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}
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if (putchar(ch) == EOF)
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oerr();
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}
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(void)fflush(stdout);
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if (ferror(file->fp)) {
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file->fp = NULL;
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ierr();
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} else
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clearerr(file->fp);
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}
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void
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set_events(file_info_t *files)
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{
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int i, n = 0;
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file_info_t *file;
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struct timespec ts;
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ts.tv_sec = 0;
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ts.tv_nsec = 0;
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action = USE_KQUEUE;
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for (i = 0, file = files; i < no_files; i++, file++) {
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if (! file->fp)
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continue;
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if (Fflag && fileno(file->fp) != STDIN_FILENO) {
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EV_SET(&ev[n], fileno(file->fp), EVFILT_VNODE,
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EV_ADD | EV_ENABLE | EV_CLEAR,
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NOTE_DELETE | NOTE_RENAME, 0, 0);
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n++;
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}
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EV_SET(&ev[n], fileno(file->fp), EVFILT_READ,
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EV_ADD | EV_ENABLE | EV_CLEAR, 0, 0, 0);
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n++;
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}
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if (kevent(kq, ev, n, NULL, 0, &ts) < 0) {
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action = USE_SLEEP;
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}
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}
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void
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follow(file_info_t *files, enum STYLE style, off_t off)
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{
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int active, i, n = -1;
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struct stat sb2;
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struct stat *sbp;
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file_info_t *file;
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long spin=1;
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struct timespec ts;
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/* Position each of the files */
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file = files;
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active = 0;
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n = 0;
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for (i = 0; i < no_files; i++, file++) {
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if (file->fp) {
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active = 1;
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n++;
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if (no_files > 1)
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(void)printf("\n==> %s <==\n", file->file_name);
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forward(file->fp, style, off, &file->st);
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if (Fflag && fileno(file->fp) != STDIN_FILENO)
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n++;
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}
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}
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if (! active)
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return;
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kq = kqueue();
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if (kq < 0)
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err(1, "kqueue");
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ev = malloc(n * sizeof(struct kevent));
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if (! ev)
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err(1, "Couldn't allocate memory for kevents.");
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set_events(files);
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for (;;) {
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for (i = 0, file = files; i < no_files; i++, file++) {
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if (! file->fp)
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continue;
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if (Fflag && file->fp && fileno(file->fp) != STDIN_FILENO) {
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if (stat(file->file_name, &sb2) != 0) {
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/* file was rotated, skip it until it reappears */
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continue;
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}
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if (sb2.st_ino != file->st.st_ino ||
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sb2.st_dev != file->st.st_dev ||
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sb2.st_nlink == 0) {
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file->fp = freopen(file->file_name, "r", file->fp);
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if (file->fp == NULL) {
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ierr();
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continue;
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} else {
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memcpy(&file->st, &sb2, sizeof(struct stat));
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set_events(files);
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}
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}
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}
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show(file);
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}
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switch (action) {
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case USE_KQUEUE:
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ts.tv_sec = 1;
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ts.tv_nsec = 0;
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/*
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* In the -F case we set a timeout to ensure that
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* we re-stat the file at least once every second.
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*/
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n = kevent(kq, NULL, 0, ev, 1, Fflag ? &ts : NULL);
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if (n < 0)
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err(1, "kevent");
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if (n == 0) {
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/* timeout */
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break;
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} else if (ev->filter == EVFILT_READ && ev->data < 0) {
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/* file shrank, reposition to end */
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if (lseek(ev->ident, (off_t)0, SEEK_END) == -1) {
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ierr();
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continue;
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}
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}
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break;
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case USE_SLEEP:
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(void) usleep(250000);
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break;
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}
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}
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}
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@ -60,9 +60,11 @@ static const char sccsid[] = "@(#)tail.c 8.1 (Berkeley) 6/6/93";
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#include "extern.h"
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int Fflag, fflag, rflag, rval;
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int Fflag, fflag, rflag, rval, no_files;
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const char *fname;
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file_info_t *files;
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static void obsolete(char **);
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static void usage(void);
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@ -73,7 +75,8 @@ main(int argc, char *argv[])
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FILE *fp;
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off_t off;
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enum STYLE style;
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int ch, first;
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int i, ch, first;
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file_info_t *file;
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char *p;
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/*
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@ -138,8 +141,7 @@ main(int argc, char *argv[])
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argc -= optind;
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argv += optind;
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if (fflag && argc > 1)
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errx(1, "-f option only appropriate for a single file");
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no_files = argc ? argc : 1;
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/*
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* If displaying in reverse, don't permit follow option, and convert
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@ -168,7 +170,29 @@ main(int argc, char *argv[])
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}
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}
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if (*argv)
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if (*argv && fflag) {
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files = (struct file_info *) malloc(no_files * sizeof(struct file_info));
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if (! files)
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err(1, "Couldn't malloc space for file descriptors.");
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for (file = files; (fname = *argv++); file++) {
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file->file_name = malloc(strlen(fname)+1);
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if (! file->file_name)
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errx(1, "Couldn't malloc space for file name.");
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strncpy(file->file_name, fname, strlen(fname)+1);
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if ((file->fp = fopen(file->file_name, "r")) == NULL ||
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fstat(fileno(file->fp), &file->st)) {
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file->fp = NULL;
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ierr();
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continue;
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}
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}
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follow(files, style, off);
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for (i = 0, file = files; i < no_files; i++, file++) {
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free(file->file_name);
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}
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free(files);
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} else if (*argv) {
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for (first = 1; (fname = *argv++);) {
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if ((fp = fopen(fname, "r")) == NULL ||
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fstat(fileno(fp), &sb)) {
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@ -186,9 +210,8 @@ main(int argc, char *argv[])
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reverse(fp, style, off, &sb);
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else
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forward(fp, style, off, &sb);
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(void)fclose(fp);
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}
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else {
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} else {
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fname = "stdin";
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if (fstat(fileno(stdin), &sb)) {
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