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/*
* cut.c - minimalist version of cut
*
* Copyright (C) 1999,2000 by Lineo, inc.
* Written by Mark Whitley <markw@lineo.com>, <markw@enol.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h> /* getopt */
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include "internal.h"
/* globals from other files */
extern int optind;
extern char *optarg;
/* globals in this file only */
static char part = 0; /* (b)yte, (c)har, (f)ields */
static int startpos = 1;
static int endpos = -1;
static char delim = '\t'; /* delimiter, default is tab */
static unsigned int supress_non_delimited_lines = 0;
/*
* decompose_list() - parses a list and puts values into startpos and endpos.
* valid list formats: N, N-, N-M, -M
*/
static void decompose_list(const char *list)
{
unsigned int nminus = 0;
char *ptr;
/* the list must contain only digits and no more than one minus sign */
for (ptr = (char *)list; *ptr; ptr++) {
if (!isdigit(*ptr) && *ptr != '-') {
fatalError("invalid byte or field list\n");
}
if (*ptr == '-') {
nminus++;
if (nminus > 1) {
fatalError("invalid byte or field list\n");
}
}
}
/* handle single value 'N' case */
if (nminus == 0) {
startpos = strtol(list, &ptr, 10);
if (startpos == 0) {
fatalError("missing list of fields\n");
}
endpos = startpos;
}
/* handle multi-value cases */
else if (nminus == 1) {
/* handle 'N-' case */
if (list[strlen(list) - 1] == '-') {
startpos = strtol(list, &ptr, 10);
}
/* handle '-M' case */
else if (list[0] == '-') {
endpos = strtol(&list[1], NULL, 10);
}
/* handle 'N-M' case */
else {
startpos = strtol(list, &ptr, 10);
endpos = strtol(ptr+1, &ptr, 10);
}
/* a sanity check */
if (startpos == 0) {
startpos = 1;
}
}
}
/*
* snippy-snip
*/
static void cut_file(FILE *file)
{
char *line;
/* go through every line in the file */
for (line = NULL; (line = get_line_from_file(file)) != NULL; free(line)) {
/* cut based on chars/bytes */
if (part == 'c' || part == 'b') {
int i;
/* a valid end position has been specified */
if (endpos > 0) {
for (i = startpos-1; i < endpos; i++) {
fputc(line[i], stdout);
}
fputc('\n', stdout);
}
/* otherwise, just go to the end of the line */
else {
for (i = startpos-1; line[i]; i++) {
fputc(line[i], stdout);
}
}
}
/* cut based on fields */
else if (part == 'f') {
char *ptr;
char *start = line;
unsigned int delims_hit = 0;
for (ptr = line; (ptr = strchr(ptr, delim)) != NULL; ptr++) {
delims_hit++;
if (delims_hit == (startpos - 1)) {
start = ptr+1;
}
if (delims_hit == endpos) {
break;
}
}
/* we didn't hit any delimeters */
if (delims_hit == 0 && !supress_non_delimited_lines) {
fputs(line, stdout);
}
/* we =did= hit some delimiters */
else if (delims_hit > 0) {
/* we have a fixed end point */
if (ptr) {
while (start < ptr) {
fputc(*start, stdout);
start++;
}
fputc('\n', stdout);
}
/* or we're just going til the end of the line */
else {
while (*start) {
fputc(*start, stdout);
start++;
}
}
}
}
}
}
extern int cut_main(int argc, char **argv)
{
int opt;
while ((opt = getopt(argc, argv, "b:c:d:f:ns")) > 0) {
switch (opt) {
case 'b':
case 'c':
case 'f':
/* make sure they didn't ask for two types of lists */
if (part != 0) {
fatalError("only one type of list may be specified");
}
part = (char)opt;
decompose_list(optarg);
break;
case 'd':
if (strlen(optarg) > 1) {
fatalError("the delimiter must be a single character\n");
}
delim = optarg[0];
break;
case 'n':
/* no-op */
break;
case 's':
supress_non_delimited_lines++;
break;
}
}
if (part == 0) {
fatalError("you must specify a list of bytes, characters, or fields\n");
}
if (supress_non_delimited_lines && part != 'f') {
fatalError("suppressing non-delimited lines makes sense
only when operating on fields\n");
}
if (delim != '\t' && part != 'f') {
fatalError("a delimiter may be specified only when operating on fields\n");
}
/* argv[(optind)..(argc-1)] should be names of file to process. If no
* files were specified or '-' was specified, take input from stdin.
* Otherwise, we process all the files specified. */
if (argv[optind] == NULL || (strcmp(argv[optind], "-") == 0)) {
cut_file(stdin);
}
else {
int i;
FILE *file;
for (i = optind; i < argc; i++) {
file = fopen(argv[i], "r");
if (file == NULL) {
errorMsg("%s: %s\n", argv[i], strerror(errno));
} else {
cut_file(file);
fclose(file);
}
}
}
return 0;
}
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