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 #ifdef HAS_STDLIB_H
15 #include <stdlib.h>
16 #endif
17 #include <string.h>
18 #ifdef HAVE_ERRNO_H
19 #include <errno.h>
20 #endif
21
22 #include "ss_internal.h"
23
24 enum parse_mode { WHITESPACE, TOKEN, QUOTED_STRING };
25
26 /*
27 * parse(line_ptr, argc_ptr)
28 *
29 * Function:
30 * Parses line, dividing at whitespace, into tokens, returns
31 * the "argc" and "argv" values.
32 * Arguments:
33 * line_ptr (char *)
34 * Pointer to text string to be parsed.
35 * argc_ptr (int *)
36 * Where to put the "argc" (number of tokens) value.
37 * Returns:
38 * argv (char **)
39 * Series of pointers to parsed tokens.
40 */
41
42 #define NEW_ARGV(old,n) (char **)realloc((char *)old,\
43 (unsigned)(n+2)*sizeof(char*))
44
ss_parse(int sci_idx,register char * line_ptr,int * argc_ptr)45 char **ss_parse(int sci_idx, register char *line_ptr, int *argc_ptr)
46 {
47 register char **argv, *cp;
48 register int argc;
49 register enum parse_mode parse_mode;
50
51 argv = (char **) malloc (sizeof(char *));
52 if (argv == (char **)NULL) {
53 ss_error(sci_idx, errno, "Can't allocate storage");
54 *argc_ptr = 0;
55 return(argv);
56 }
57 *argv = (char *)NULL;
58
59 argc = 0;
60
61 parse_mode = WHITESPACE; /* flushing whitespace */
62 cp = line_ptr; /* cp is for output */
63 while (1) {
64 #ifdef DEBUG
65 {
66 printf ("character `%c', mode %d\n", *line_ptr, parse_mode);
67 }
68 #endif
69 while (parse_mode == WHITESPACE) {
70 if (*line_ptr == '\0')
71 goto end_of_line;
72 if (*line_ptr == ' ' || *line_ptr == '\t') {
73 line_ptr++;
74 continue;
75 }
76 if (*line_ptr == '"') {
77 /* go to quoted-string mode */
78 parse_mode = QUOTED_STRING;
79 cp = line_ptr++;
80 argv = NEW_ARGV (argv, argc);
81 argv[argc++] = cp;
82 argv[argc] = NULL;
83 }
84 else {
85 /* random-token mode */
86 parse_mode = TOKEN;
87 cp = line_ptr;
88 argv = NEW_ARGV (argv, argc);
89 if (argv == NULL) {
90 *argc_ptr = errno;
91 return argv;
92 }
93 argv[argc++] = line_ptr;
94 argv[argc] = NULL;
95 }
96 }
97 while (parse_mode == TOKEN) {
98 if (*line_ptr == '\0') {
99 *cp++ = '\0';
100 goto end_of_line;
101 }
102 else if (*line_ptr == ' ' || *line_ptr == '\t') {
103 *cp++ = '\0';
104 line_ptr++;
105 parse_mode = WHITESPACE;
106 }
107 else if (*line_ptr == '"') {
108 line_ptr++;
109 parse_mode = QUOTED_STRING;
110 }
111 else {
112 *cp++ = *line_ptr++;
113 }
114 }
115 while (parse_mode == QUOTED_STRING) {
116 if (*line_ptr == '\0') {
117 ss_error (sci_idx, 0,
118 "Unbalanced quotes in command line");
119 free (argv);
120 *argc_ptr = 0;
121 return NULL;
122 }
123 else if (*line_ptr == '"') {
124 if (*++line_ptr == '"') {
125 *cp++ = '"';
126 line_ptr++;
127 }
128 else {
129 parse_mode = TOKEN;
130 }
131 }
132 else {
133 *cp++ = *line_ptr++;
134 }
135 }
136 }
137 end_of_line:
138 *argc_ptr = argc;
139 #ifdef DEBUG
140 {
141 int i;
142 printf ("argc = %d\n", argc);
143 for (i = 0; i <= argc; i++)
144 printf ("\targv[%2d] = `%s'\n", i,
145 argv[i] ? argv[i] : "<NULL>");
146 }
147 #endif
148 return(argv);
149 }
150