1 /*
2 *+
3 * Name:
4 * palIntin
5
6 * Purpose:
7 * Convert free-format input into an integer
8
9 * Language:
10 * Starlink ANSI C
11
12 * Type of Module:
13 * Library routine
14
15 * Invocation:
16 * void palIntin( const char * string, int *nstrt,
17 * long *ireslt, int *jflag );
18
19 * Arguments:
20 * string = const char * (Given)
21 * String containing number to be decoded.
22 * nstrt = int * (Given and Returned)
23 * Character number indicating where decoding should start.
24 * On output its value is updated to be the location of the
25 * possible next value. For compatibility with SLA the first
26 * character is index 1.
27 * ireslt = long * (Returned)
28 * Result. Not updated when jflag=1.
29 * jflag = int * (Returned)
30 * status: -1 = -OK, 0 = +OK, 1 = null, 2 = error
31
32 * Description:
33 * Extracts a number from an input string starting at the specified
34 * index.
35
36 * Authors:
37 * TIMJ: Tim Jenness (JAC, Hawaii)
38 * {enter_new_authors_here}
39
40 * Notes:
41 * - Uses the strtol() system call to do the parsing. This may lead to
42 * subtle differences when compared to the SLA/F parsing.
43 * - Commas are recognized as a special case and are skipped if one happens
44 * to be the next character when updating nstrt. Additionally the output
45 * nstrt position will skip past any trailing space.
46 * - If no number can be found flag will be set to 1.
47 * - If the number overflows or underflows jflag will be set to 2. For overflow
48 * the returned result will have the value LONG_MAX, for underflow it
49 * will have the value LONG_MIN.
50
51 * History:
52 * 2012-03-15 (TIMJ):
53 * Initial version
54 * Matches the SLALIB interface but brand new implementation using
55 * C library calls and not a direct port of the Fortran.
56 * 2014-08-07 (TIMJ):
57 * Check for isblank availability.
58 * {enter_further_changes_here}
59
60 * Copyright:
61 * Copyright (C) 2012,2014 Science and Technology Facilities Council.
62 * All Rights Reserved.
63
64 * Licence:
65 * This program is free software; you can redistribute it and/or
66 * modify it under the terms of the GNU General Public License as
67 * published by the Free Software Foundation; either version 3 of
68 * the License, or (at your option) any later version.
69 *
70 * This program is distributed in the hope that it will be
71 * useful, but WITHOUT ANY WARRANTY; without even the implied
72 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
73 * PURPOSE. See the GNU General Public License for more details.
74 *
75 * You should have received a copy of the GNU General Public License
76 * along with this program; if not, write to the Free Software
77 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
78 * MA 02110-1301, USA.
79
80 * Bugs:
81 * {note_any_bugs_here}
82 *-
83 */
84
85 #if HAVE_CONFIG_H
86 # include <config.h>
87 #endif
88
89 #include <stdlib.h>
90 #include <errno.h>
91
92 /* isblank() is a C99 feature so we just reimplement it if it is missing */
93 #if HAVE_ISBLANK
94 #ifndef _ISOC99_SOURCE
95 #define _ISOC99_SOURCE
96 #endif
97 #include <ctype.h>
98 # define ISBLANK isblank
99 #else
100
ISBLANK(int c)101 static int ISBLANK( int c ) {
102 return ( c == ' ' || c == '\t' );
103 }
104
105 #endif
106
107 /* Still need ctype for isalpha and isdigit */
108 #include <ctype.h>
109
110 #include "pal.h"
111
palIntin(const char * string,int * nstrt,long * ireslt,int * jflag)112 void palIntin( const char * string, int *nstrt,
113 long *ireslt, int *jflag ) {
114
115 const char *strstart = NULL; /* Pointer to start of search */
116 const char * ctemp = NULL; /* Pointer into string */
117 char * endptr = NULL;/* Pointer to string after number */
118 int retval; /* Return value from strtol */
119 int hasminus; /* is this a -0 */
120
121 /* strtol man page indicates that we should reset errno before
122 calling strtod */
123 errno = 0;
124
125 /* Locate the start postion */
126 strstart = &(string[*nstrt-1]);
127
128 /* We have to be able to deal with -0 so we have to search the
129 string first and look for the negative */
130 hasminus = 0;
131 ctemp = strstart;
132 while ( *ctemp != '\0' ) {
133 if (isdigit(*ctemp)) break;
134 /* Reset so that - 12345 is not a negative number */
135 hasminus = 0;
136 /* Flag that we have found a minus */
137 if (*ctemp == '-') hasminus = 1;
138 ctemp++;
139 }
140
141 /* Look for the number using the system call, offsetting using
142 1-based counter. */
143 retval = strtol( strstart, &endptr, 10 );
144 if (retval == 0.0 && endptr == strstart) {
145 /* conversion did not find anything */
146 *jflag = 1;
147
148 /* but SLA compatibility requires that we step
149 through to remove leading spaces. We also step
150 through alphabetic characters since they can never
151 be numbers. Skip past a "+" since it doesn't gain
152 us anything and matches slalib. */
153 while (ISBLANK(*endptr) || isalpha(*endptr) || *endptr == '+' ) {
154 endptr++;
155 }
156
157 } else if ( errno == ERANGE ) {
158 *jflag = 2;
159 } else {
160 if ( retval < 0 || hasminus ) {
161 *jflag = -1;
162 } else {
163 *jflag = 0;
164 }
165 }
166
167 /* Sort out the position for the next index */
168 *nstrt = endptr - string + 1;
169
170 /* Skip a comma */
171 if (*endptr == ',') {
172 (*nstrt)++;
173 } else {
174 /* jump past any leading spaces for the next part of the string */
175 ctemp = endptr;
176 while ( ISBLANK(*ctemp) ) {
177 (*nstrt)++;
178 ctemp++;
179 }
180 }
181
182 /* And the result unless we found nothing */
183 if (*jflag != 1) *ireslt = retval;
184
185 }
186