126 lines
3.2 KiB
C
126 lines
3.2 KiB
C
/*
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* str.c - String helper functions that don't need string.h or ctype.h
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*
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* Copyright (C) 2006 Red Hat, Inc. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* Author(s): David Cantrell <dcantrell@redhat.com>
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include "str.h"
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/**
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* Called by str2upper() or str2lower() to do the actual work.
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*
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* @param str String to convert.
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* @param lower Lower bound for the character range (e.g., a - z).
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* @param upper Upper bound for the character range (e.g., a - z).
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* @param shift Shift value (32 for lowercase, -32 for uppercase).
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* @return Pointer to str.
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*/
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char *str2case(char *str, char lower, char upper, int shift) {
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char *tmp;
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if (str == NULL)
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return NULL;
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/* man ascii(7) */
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tmp = str;
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while (*tmp != '\0') {
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if (*tmp >= lower && *tmp <= upper)
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*tmp += shift;
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tmp++;
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}
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return str;
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}
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/**
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* Convert given string to uppercase. Modifies the argument in the caller's
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* stack. If you must ask simply "why?" for this function, it's so we don't
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* need toupper() and the same for loop all over the place.
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*
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* LIMITATIONS: Only deals with ASCII character set.
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*
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* @param str String to convert to uppercase.
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* @return Pointer to str.
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*/
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char *str2upper(char *str) {
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return str2case(str, 'a', 'z', -32);
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}
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/**
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* Convert given string to lowercase. Modifies the argument in the caller's
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* stack. If you must ask simply "why?" for this function, it's so we don't
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* need tolower() and the same for loop all over the place.
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*
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* LIMITATIONS: Only deals with ASCII character set.
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*
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* @param str String to convert to lowercase.
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* @return Pointer to str.
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*/
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char *str2lower(char *str) {
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return str2case(str, 'A', 'Z', 32);
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}
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/**
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* Pretty much an exact copy of index(3) from the C library.
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* @param str String to scan.
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* @param ch Character to scan for.
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* @return Position of ch in str, NULL if not found.
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*/
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char *strindex(char *str, int ch) {
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if (str == NULL)
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return NULL;
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do {
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if (*str == ch)
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return str;
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else
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str++;
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} while (*str != '\0');
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return NULL;
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}
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/**
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* Return number of occurrences of a character in a string.
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* @param str String to scan.
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* @param ch Character to scan for.
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* @return Number of occurrences of ch in str.
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*/
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int strcount(char *str, int ch) {
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int retval = 0;
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char *tmp = str;
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if (tmp == NULL)
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return retval;
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do {
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if ((tmp = strindex(tmp, ch)) != NULL) {
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tmp++;
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retval++;
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}
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} while (tmp != NULL);
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return retval;
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}
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/* vim:set shiftwidth=4 softtabstop=4: */
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