1 /*
2 * Copyright 1987, 1988 by MIT Student Information Processing Board
3 *
4 * Permission to use, copy, modify, and distribute this software and
5 * its documentation for any purpose is hereby granted, provided that
6 * the names of M.I.T. and the M.I.T. S.I.P.B. not be used in
7 * advertising or publicity pertaining to distribution of the software
8 * without specific, written prior permission. M.I.T. and the
9 * M.I.T. S.I.P.B. make no representations about the suitability of
10 * this software for any purpose. It is provided "as is" without
11 * express or implied warranty.
12 */
13
14 #include "config.h"
15 #ifdef HAS_STDLIB_H
16 #include <stdlib.h>
17 #endif
18 #include <string.h>
19 #ifdef HAVE_ERRNO_H
20 #include <errno.h>
21 #endif
22
23 #include "ss_internal.h"
24
25 enum parse_mode { WHITESPACE, TOKEN, QUOTED_STRING };
26
27 /*
28 * parse(line_ptr, argc_ptr)
29 *
30 * Function:
31 * Parses line, dividing at whitespace, into tokens, returns
32 * the "argc" and "argv" values.
33 * Arguments:
34 * line_ptr (char *)
35 * Pointer to text string to be parsed.
36 * argc_ptr (int *)
37 * Where to put the "argc" (number of tokens) value.
38 * Returns:
39 * argv (char **)
40 * Series of pointers to parsed tokens.
41 */
42
43 #define NEW_ARGV(old,n) (char **)realloc((char *)old,\
44 (unsigned)(n+2)*sizeof(char*))
45
ss_parse(int sci_idx,register char * line_ptr,int * argc_ptr)46 char **ss_parse(int sci_idx, register char *line_ptr, int *argc_ptr)
47 {
48 register char **argv, **new_argv, *cp;
49 register int argc;
50 register enum parse_mode parse_mode;
51
52 argv = (char **) malloc (sizeof(char *));
53 if (argv == (char **)NULL) {
54 ss_error(sci_idx, errno, "Can't allocate storage");
55 *argc_ptr = 0;
56 return(argv);
57 }
58 *argv = (char *)NULL;
59
60 argc = 0;
61
62 parse_mode = WHITESPACE; /* flushing whitespace */
63 cp = line_ptr; /* cp is for output */
64 while (1) {
65 #ifdef DEBUG
66 {
67 printf ("character `%c', mode %d\n", *line_ptr, parse_mode);
68 }
69 #endif
70 while (parse_mode == WHITESPACE) {
71 if (*line_ptr == '\0')
72 goto end_of_line;
73 if (*line_ptr == ' ' || *line_ptr == '\t') {
74 line_ptr++;
75 continue;
76 }
77 if (*line_ptr == '"') {
78 /* go to quoted-string mode */
79 parse_mode = QUOTED_STRING;
80 cp = line_ptr++;
81 new_argv = NEW_ARGV (argv, argc);
82 if (new_argv == NULL) {
83 free(argv);
84 *argc_ptr = 0;
85 return NULL;
86 }
87 argv = new_argv;
88 argv[argc++] = cp;
89 argv[argc] = NULL;
90 }
91 else {
92 /* random-token mode */
93 parse_mode = TOKEN;
94 cp = line_ptr;
95 new_argv = NEW_ARGV (argv, argc);
96 if (new_argv == NULL) {
97 free(argv);
98 *argc_ptr = 0;
99 return NULL;
100 }
101 argv = new_argv;
102 argv[argc++] = line_ptr;
103 argv[argc] = NULL;
104 }
105 }
106 while (parse_mode == TOKEN) {
107 if (*line_ptr == '\0') {
108 *cp++ = '\0';
109 goto end_of_line;
110 }
111 else if (*line_ptr == ' ' || *line_ptr == '\t') {
112 *cp++ = '\0';
113 line_ptr++;
114 parse_mode = WHITESPACE;
115 }
116 else if (*line_ptr == '"') {
117 line_ptr++;
118 parse_mode = QUOTED_STRING;
119 }
120 else {
121 *cp++ = *line_ptr++;
122 }
123 }
124 while (parse_mode == QUOTED_STRING) {
125 if (*line_ptr == '\0') {
126 ss_error (sci_idx, 0,
127 "Unbalanced quotes in command line");
128 free (argv);
129 *argc_ptr = 0;
130 return NULL;
131 }
132 else if (*line_ptr == '"') {
133 if (*++line_ptr == '"') {
134 *cp++ = '"';
135 line_ptr++;
136 }
137 else {
138 parse_mode = TOKEN;
139 }
140 }
141 else {
142 *cp++ = *line_ptr++;
143 }
144 }
145 }
146 end_of_line:
147 *argc_ptr = argc;
148 #ifdef DEBUG
149 {
150 int i;
151 printf ("argc = %d\n", argc);
152 for (i = 0; i <= argc; i++)
153 printf ("\targv[%2d] = `%s'\n", i,
154 argv[i] ? argv[i] : "<NULL>");
155 }
156 #endif
157 return(argv);
158 }
159