/* lx4sgn.f -- translated by f2c (version 19980913).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include "f2c.h"

/* $Procedure      LX4SGN (Scan for signed integer) */
/* Subroutine */ int lx4sgn_(char *string, integer *first, integer *last, 
	integer *nchar, ftnlen string_len)
{
    /* Builtin functions */
    integer i_len(char *, ftnlen);

    /* Local variables */
    integer f, i__, l;
    extern /* Subroutine */ int lx4uns_(char *, integer *, integer *, integer 
	    *, ftnlen);

/* $ Abstract */

/*     Scan a string from a specified starting position for the */
/*     end of a signed integer. */


/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Required_Reading */

/*      None. */

/* $ Keywords */

/*       PARSING */

/* $ Declarations */
/* $ Brief_I/O */

/*      VARIABLE  I/O  DESCRIPTION */
/*      --------  ---  -------------------------------------------------- */
/*      STRING     I   any character string */
/*      FIRST      I   first character to scan from in STRING */
/*      LAST       O   last character that is part of a signed integer */
/*      NCHAR      O   number of characters in the signed integer. */

/* $ Detailed_Input */

/*     STRING      is any character string. */

/*     FIRST       is the location in the string to beginning scanning */
/*                 for a signed integer.  It is assumed that the */
/*                 signed integer begins at FIRST. */

/* $ Detailed_Output */

/*     LAST        is the last character at or after FIRST such that */
/*                 the substring STRING(FIRST:LAST) is a signed */
/*                 integer.  If there is no such substring, LAST */
/*                 will be returned with the value FIRST-1. */

/*     NCHAR       is the number of characters in the signed integer */
/*                 that begins at FIRST and ends at last.  If there */
/*                 is no such string NCHAR will be given the value 0. */

/* $ Parameters */

/*      None. */

/* $ Files */

/*      None. */

/* $ Exceptions */

/*     Error free. */

/*     1) If FIRST is beyond either end of the string, then */
/*        LAST will be returned with the value FIRST and NCHAR */
/*        will be returned with the value 0. */

/*     2) If STRING(FIRST:FIRST) is not part of a signed integer */
/*        then LAST will be returned with the value FIRST-1 and NCHAR */
/*        will be returned with the value 0. */

/* $ Particulars */

/*     This routine allows you to scan forward in a string to locate */
/*     a signed integer that begins on the input character FIRST.  Note */
/*     that all unsigned integers are included in the list of signed */
/*     integers.  The signed integers may in addition have a leading */
/*     plus ('+') or minus ('-') sign. */


/* $ Examples */

/*     Suppose you believe that a string has the form */

/*        X%Y%Z */

/*     where X, Y, and Z are signed integers of some unknown */
/*     length and % stands for some non-digit character. You could */
/*     use this routine to locate the signed integers in the */
/*     string as shown below.  We'll keep track of the beginning and */
/*     ending of the signed integers in the integer arrays B and E. */

/*     FIRST = 1 */
/*     I     = 0 */

/*     DO WHILE ( FIRST .LT. LEN(STRING) ) */

/*        CALL LX4SGN ( STRING, FIRST, LAST, NCHAR ) */

/*        IF ( NCHAR .GT. 0 ) THEN */

/*           I     = I    + 1 */
/*           B(I)  = FIRST */
/*           E(I)  = LAST */
/*           FIRST = LAST + 2 */

/*        ELSE */

/*           FIRST = FIRST + 1 */

/*        END IF */

/*     END DO */


/* $ Restrictions */

/*     None. */

/* $ Author_and_Institution */

/*      W.L. Taber      (JPL) */

/* $ Literature_References */

/*      None. */

/* $ Version */

/* -    SPICELIB Version 1.0.0, 12-JUL-1994 (WLT) */


/* -& */
/* $ Index_Entries */

/*     Scan a string for a signed integer. */

/* -& */
    *last = *first - 1;
    l = i_len(string, string_len);

/*     If start is beyond the ends of the string, we  can quit now. */

    if (*first < 1 || *first > l) {
	*nchar = 0;
	return 0;
    }

/*     There are two cases to take care of (and in both cases */
/*     LX4UNS does almost all of the work). */

    i__ = *(unsigned char *)&string[*first - 1];
    if (i__ == '+' || i__ == '-') {

/*        Case 1. The string begins with a + or -.  There must */
/*        be an unsigned integer following. */

	f = *first + 1;
	lx4uns_(string, &f, last, nchar, string_len);
	if (*nchar == 0) {
	    *last = *first - 1;
	} else {
	    ++(*nchar);
	}
    } else {

/*        Case 2.  The leading character is not a sign character. */
/*        We simply check to see how much unsigned integer we have. */

	lx4uns_(string, first, last, nchar, string_len);
    }
    return 0;
} /* lx4sgn_ */

