void lx4sgn_c ( ConstSpiceChar * string,
SpiceInt * last,
SpiceInt * nchar )
Scan a string from a specified starting position for the
end of a signed integer.
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.
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.
The normal range of first is 0 : strlen(string)-1.
last is the last character at or after first such that the
substring ranging from string[first] through
string[last] is a signed integer. If there is no such
substring, last will be returned with the value first-1.
If a signed integer is found, last will be in the
range is 0 : strlen(string)-1.
nchar is the number of characters in the signed integer that
begins at index first and ends at last. If there is no
such string nchar will be given the value 0.
1) If first is beyond either end of the string, then
last will be returned with the value first-1 and nchar
will be returned with the value 0.
2) If string[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.
3) If the input string pointer is null, the error SPICE(NULLPOINTER)
will be signaled.
4) If the input string has length zero, last will be set to first-1
and nchar will be set to zero. This case is not considered an
This routine allows you to scan forward in a string to locate a
signed integer that begins on the input character at index 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.
1) Suppose you believe that a string has the form
where X, Y, and Z are signed integers of some unknown length and
% stands for any character that cannot occur in a signed integer.
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 = 0;
i = 0;
len = strlen(string);
while ( first < len-1 )
lx4sgn_c ( string, first, &last, &nchar );
if ( nchar > 0 )
b[i] = first;
e[i] = last;
first = last + 2;
N.J. Bachman (JPL)
W.L. Taber (JPL)
-CSPICE Version 1.0.0, 18-AUG-2002 (NJB) (WLT)
Scan a string for a signed integer.