/**
* \file streqvcmp.c
*
* String Equivalence Comparison
*
* These routines allow any character to be mapped to any other
* character before comparison. In processing long option names,
* the characters "-", "_" and "^" all need to be equivalent
* (because they are treated so by different development environments).
*
* @addtogroup autoopts
* @{
*/
/*
* This file is part of AutoOpts, a companion to AutoGen.
* AutoOpts is free software.
* AutoOpts is Copyright (C) 1992-2018 by Bruce Korb - all rights reserved
*
* AutoOpts is available under any one of two licenses. The license
* in use must be one of these two and the choice is under the control
* of the user of the license.
*
* The GNU Lesser General Public License, version 3 or later
* See the files "COPYING.lgplv3" and "COPYING.gplv3"
*
* The Modified Berkeley Software Distribution License
* See the file "COPYING.mbsd"
*
* These files have the following sha256 sums:
*
* 8584710e9b04216a394078dc156b781d0b47e1729104d666658aecef8ee32e95 COPYING.gplv3
* 4379e7444a0e2ce2b12dd6f5a52a27a4d02d39d247901d3285c88cf0d37f477b COPYING.lgplv3
* 13aa749a5b0a454917a944ed8fffc530b784f5ead522b1aacaf4ec8aa55a6239 COPYING.mbsd
*
* This array is designed for mapping upper and lower case letter
* together for a case independent comparison. The mappings are
* based upon ascii character sequences.
*/
static unsigned char charmap[] = {
NUL, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, '\a',
'\b', '\t', NL, '\v', '\f', '\r', 0x0E, 0x0F,
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
/*=export_func strneqvcmp
*
* what: compare two strings with an equivalence mapping
*
* arg: + char const * + str1 + first string +
* arg: + char const * + str2 + second string +
* arg: + int + ct + compare length +
*
* ret_type: int
* ret_desc: the difference between two differing characters
*
* doc:
*
* Using a character mapping, two strings are compared for "equivalence".
* Each input character is mapped to a comparison character and the
* mapped-to characters are compared for the two NUL terminated input strings.
* The comparison is limited to @code{ct} bytes.
* This function name is mapped to option_strneqvcmp so as to not conflict
* with the POSIX name space.
*
* err: none checked. Caller responsible for seg faults.
=*/
int
strneqvcmp(char const * s1, char const * s2, int ct)
{
for (; ct > 0; --ct) {
unsigned char u1 = (unsigned char) *s1++;
unsigned char u2 = (unsigned char) *s2++;
int dif;
if (u1 == u2) {
if (u1 == NUL)
return 0;
continue;
}
dif = charmap[ u1 ] - charmap[ u2 ];
if (dif != 0)
return dif;
if (u1 == NUL)
return 0;
}
return 0;
}
/*=export_func streqvcmp
*
* what: compare two strings with an equivalence mapping
*
* arg: + char const * + str1 + first string +
* arg: + char const * + str2 + second string +
*
* ret_type: int
* ret_desc: the difference between two differing characters
*
* doc:
*
* Using a character mapping, two strings are compared for "equivalence".
* Each input character is mapped to a comparison character and the
* mapped-to characters are compared for the two NUL terminated input strings.
* This function name is mapped to option_streqvcmp so as to not conflict
* with the POSIX name space.
*
* err: none checked. Caller responsible for seg faults.
=*/
int
streqvcmp(char const * s1, char const * s2)
{
for (;;) {
unsigned char u1 = (unsigned char) *s1++;
unsigned char u2 = (unsigned char) *s2++;
int dif;
if (u1 == u2) {
if (u1 == NUL)
return 0;
continue;
}
dif = charmap[ u1 ] - charmap[ u2 ];
if (dif != 0)
return dif;
if (u1 == NUL)
return 0;
}
}
/*=export_func streqvmap
*
* what: Set the character mappings for the streqv functions
*
* arg: + char + from + Input character +
* arg: + char + to + Mapped-to character +
* arg: + int + ct + compare length +
*
* doc:
*
* Set the character mapping. If the count (@code{ct}) is set to zero, then
* the map is cleared by setting all entries in the map to their index
* value. Otherwise, the "@code{From}" character is mapped to the "@code{To}"
* character. If @code{ct} is greater than 1, then @code{From} and @code{To}
* are incremented and the process repeated until @code{ct} entries have been
* set. For example,
* @example
* streqvmap('a', 'A', 26);
* @end example
* @noindent
* will alter the mapping so that all English lower case letters
* will map to upper case.
*
* This function name is mapped to option_streqvmap so as to not conflict
* with the POSIX name space.
*
* err: none.
=*/
void
streqvmap(char from, char to, int ct)
{
if (ct == 0) {
ct = sizeof(charmap) - 1;
do {
charmap[ct] = (unsigned char)ct;
} while (--ct >= 0);
}
else {
unsigned int i_to = (int)to & 0xFF;
unsigned int i_from = (int)from & 0xFF;
do {
charmap[i_from] = (unsigned char)i_to;
i_from++;
i_to++;
if ((i_from >= sizeof(charmap)) || (i_to >= sizeof(charmap)))
break;
} while (--ct > 0);
}
}
/*=export_func strequate
*
* what: map a list of characters to the same value
*
* arg: + char const * + ch_list + characters to equivalence +
*
* doc:
*
* Each character in the input string get mapped to the first character
* in the string.
* This function name is mapped to option_strequate so as to not conflict
* with the POSIX name space.
*
* err: none.
=*/
void
strequate(char const * s)
{
if ((s != NULL) && (*s != NUL)) {
unsigned char equiv = (unsigned char)*s;
while (*s != NUL)
charmap[(unsigned char)*(s++)] = equiv;
}
}
/*=export_func strtransform
*
* what: convert a string into its mapped-to value
*
* arg: + char * + dest + output string +
* arg: + char const * + src + input string +
*
* doc:
*
* Each character in the input string is mapped and the mapped-to
* character is put into the output.
* This function name is mapped to option_strtransform so as to not conflict
* with the POSIX name space.
*
* The source and destination may be the same.
*
* err: none.
=*/
void
strtransform(char * d, char const * s)
{
do {
*(d++) = (char)charmap[(unsigned char)*s];
} while (*(s++) != NUL);
}
/** @}
*
* Local Variables:
* mode: C
* c-file-style: "stroustrup"
* indent-tabs-mode: nil
* End:
* end of autoopts/streqvcmp.c */
