archie/tcl7.6/compat/strtol.c

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/*
* strtol.c --
*
* Source code for the "strtol" library procedure.
*
* Copyright (c) 1988 The Regents of the University of California.
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* Copyright (c) 1994 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* SCCS: @(#) strtol.c 1.4 96/02/15 12:08:23
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*/
#include <ctype.h>
/*
*----------------------------------------------------------------------
*
* strtol --
*
* Convert an ASCII string into an integer.
*
* Results:
* The return value is the integer equivalent of string. If endPtr
* is non-NULL, then *endPtr is filled in with the character
* after the last one that was part of the integer. If string
* doesn't contain a valid integer value, then zero is returned
* and *endPtr is set to string.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
long int
strtol(string, endPtr, base)
char *string; /* String of ASCII digits, possibly
* preceded by white space. For bases
* greater than 10, either lower- or
* upper-case digits may be used.
*/
char **endPtr; /* Where to store address of terminating
* character, or NULL. */
int base; /* Base for conversion. Must be less
* than 37. If 0, then the base is chosen
* from the leading characters of string:
* "0x" means hex, "0" means octal, anything
* else means decimal.
*/
{
register char *p;
int result;
/*
* Skip any leading blanks.
*/
p = string;
while (isspace(*p)) {
p += 1;
}
/*
* Check for a sign.
*/
if (*p == '-') {
p += 1;
result = -(strtoul(p, endPtr, base));
} else {
if (*p == '+') {
p += 1;
}
result = strtoul(p, endPtr, base);
}
if ((result == 0) && (endPtr != 0) && (*endPtr == p)) {
*endPtr = string;
}
return result;
}