/*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Edward Sze-Tyan Wang. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * 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. */ #include <sys/types.h> #include <sys/stat.h> #include <err.h> #include <errno.h> #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <libcasper.h> #include <casper/cap_fileargs.h> #include "extern.h" /* * bytes -- read bytes to an offset from the end and display. * * This is the function that reads to a byte offset from the end of the input, * storing the data in a wrap-around buffer which is then displayed. If the * rflag is set, the data is displayed in lines in reverse order, and this * routine has the usual nastiness of trying to find the newlines. Otherwise, * it is displayed from the character closest to the beginning of the input to * the end. */ int bytes(FILE *fp, const char *fn, off_t off) { int ch, len, tlen; char *ep, *p, *t; int wrap; char *sp; if ((sp = p = malloc(off)) == NULL) err(1, "failed to allocate memory"); for (wrap = 0, ep = p + off; (ch = getc(fp)) != EOF;) { *p = ch; if (++p == ep) { wrap = 1; p = sp; } } if (ferror(fp)) { ierr(fn); free(sp); return 1; } if (rflag) { for (t = p - 1, len = 0; t >= sp; --t, ++len) if (*t == '\n' && len) { WR(t + 1, len); len = 0; } if (wrap) { tlen = len; for (t = ep - 1, len = 0; t >= p; --t, ++len) if (*t == '\n') { if (len) { WR(t + 1, len); len = 0; } if (tlen) { WR(sp, tlen); tlen = 0; } } if (len) WR(t + 1, len); if (tlen) WR(sp, tlen); } } else { if (wrap && (len = ep - p)) WR(p, len); len = p - sp; if (len) WR(sp, len); } free(sp); return 0; } /* * lines -- read lines to an offset from the end and display. * * This is the function that reads to a line offset from the end of the input, * storing the data in an array of buffers which is then displayed. If the * rflag is set, the data is displayed in lines in reverse order, and this * routine has the usual nastiness of trying to find the newlines. Otherwise, * it is displayed from the line closest to the beginning of the input to * the end. */ int lines(FILE *fp, const char *fn, off_t off) { struct { int blen; u_int len; char *l; } *llines; int ch, rc; char *p, *sp; int blen, cnt, recno, wrap; if ((llines = calloc(off, sizeof(*llines))) == NULL) err(1, "failed to allocate memory"); p = sp = NULL; blen = cnt = recno = wrap = 0; rc = 0; while ((ch = getc(fp)) != EOF) { if (++cnt > blen) { if ((sp = realloc(sp, blen += 1024)) == NULL) err(1, "failed to allocate memory"); p = sp + cnt - 1; } *p++ = ch; if (ch == '\n') { if ((int)llines[recno].blen < cnt) { llines[recno].blen = cnt + 256; if ((llines[recno].l = realloc(llines[recno].l, llines[recno].blen)) == NULL) err(1, "failed to allocate memory"); } bcopy(sp, llines[recno].l, llines[recno].len = cnt); cnt = 0; p = sp; if (++recno == off) { wrap = 1; recno = 0; } } } if (ferror(fp)) { ierr(fn); rc = 1; goto done; } if (cnt) { llines[recno].l = sp; sp = NULL; llines[recno].len = cnt; if (++recno == off) { wrap = 1; recno = 0; } } if (rflag) { for (cnt = recno - 1; cnt >= 0; --cnt) WR(llines[cnt].l, llines[cnt].len); if (wrap) for (cnt = off - 1; cnt >= recno; --cnt) WR(llines[cnt].l, llines[cnt].len); } else { if (wrap) for (cnt = recno; cnt < off; ++cnt) WR(llines[cnt].l, llines[cnt].len); for (cnt = 0; cnt < recno; ++cnt) WR(llines[cnt].l, llines[cnt].len); } done: for (cnt = 0; cnt < off; cnt++) free(llines[cnt].l); free(sp); free(llines); return (rc); }
