home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Power CD-ROM!! 7
/
POWERCD7.ISO
/
prgmming
/
clipper
/
atdiff.c
< prev
next >
Wrap
C/C++ Source or Header
|
1993-10-14
|
2KB
|
84 lines
/*
* GT CLIPPER STANDARD HEADER
*
* File......: atdiff.c
* Author....: Andy M Leighton
* BBS.......: The Dark Knight Returns
* Net/Node..: 050/069
* User Name.: Andy Leighton
* Date......: 23/05/93
* Revision..: 1.00
*
* This is an original work by Andy Leighton and is placed in the
* public domain.
*
* Modification history:
* ---------------------
*
* $Log$
*
*/
/*
* $DOC$
* $FUNCNAME$
* GT_ATDIFF()
* $CATEGORY$
* String
* $ONELINER$
* Return the position where two strings begin to differ
* $SYNTAX$
* GT_AtDiff(<cStr1>, <cStr2>) --> nPos
* $ARGUMENTS$
* <cStr1> - A character string to compare
* <cStr2> - The string to compare with
* $RETURNS$
* nPos - The position in <cStr2> where <cStr1> begins to differ
* $DESCRIPTION$
* Return the position in <cStr2> where <cStr1> begins to differ.
* If the strings differ in the first character GT_AtDiff() will
* return 1. If the two strings are identical (or identical upto
* the last character in <cStr2>) the function will return 0.
*
* NOTE:
* invalid parameters will return -1
* $EXAMPLES$
* ? gt_atDiff("the cat", "the rat") // prints 5
* ? gt_atDiff("the cat", "the ") // prints 0
*
* $END$
*/
#include "extend.h"
CLIPPER
gt_atdiff()
{
char *s1, *s2;
int pos, len;
if (ISCHAR(1) && ISCHAR(2)) {
s1 = _parc(1);
s2 = _parc(2);
len = _parclen(2);
/*
loop through comparing both strings
NOTE: pos starts at 1, so as to return a string index
for CLIPPER
*/
for (pos = 1; (pos <= len) && (*s1 == *s2); s2++, s1++)
pos++;
if (pos > len) // strings match exactly!!!
_retni(0);
else
_retni(pos);
} else {
_retni(-1); // parameter mismatch - error -1
}
}