> Date: Fri, 8 Feb 2002 10:37:55 -0800 > From: Jim Hill <[EMAIL PROTECTED]>
> I'll note that neither GNU's head nor FreeBSD's will work properly with > David Korn's example: GNU head uses `read(fd,buff,BUFSIZE)` and doesn't > lseek at the end; and FreeBSD's uses a getc-putc loop and doesn't > fflush() at the end. Here's a patch to GNU head to fix that bug. Note to textutils maintainer: David Korn's example: `(head -n 5 >/dev/null;cat) < file' would successfully behead the first 5 lines of file. See: http://www.opengroup.org/sophocles/show_mail.tpl?source=L&listname=austin-group-l&id=3609 2002-02-08 Paul Eggert <[EMAIL PROTECTED]> * src/head.c (head_lines): If we have read too much data, try to seek back to the position we would have gotten to had we been reading one byte at a time. POSIX currently doesn't require this, but it's easy to do and some software relies on it. --- src/head.c-orig Sat Dec 1 09:29:26 2001 +++ src/head.c Fri Feb 8 14:29:20 2002 @@ -175,7 +175,16 @@ head_lines (const char *filename, int fd break; while (bytes_to_write < bytes_read) if (buffer[bytes_to_write++] == '\n' && --lines_to_write == 0) - break; + { + if (lseek (fd, bytes_to_write - bytes_read, SEEK_CUR) < 0) + { + int e = errno; + struct stat st; + if (fstat (fd, &st) != 0 || S_ISREG (st.st_mode)) + error (0, e, _("lseek error")); + } + break; + } if (fwrite (buffer, 1, bytes_to_write, stdout) == 0) error (EXIT_FAILURE, errno, _("write error")); } _______________________________________________ Bug-textutils mailing list [EMAIL PROTECTED] http://mail.gnu.org/mailman/listinfo/bug-textutils
