1/*
2 * Redistribution and use in source and binary forms, with or without
3 * modification, are permitted provided that the following conditions
4 * are met:
5 * 1. Redistributions of source code must retain the above copyright
6 * notice, this list of conditions and the following disclaimer.
7 * 2. Redistributions in binary form must reproduce the above copyright
8 * notice, this list of conditions and the following disclaimer in the
9 * documentation and/or other materials provided with the distribution.
10 *
11 * Jordan K. Hubbard
12 * 29 August 1998
13 *
| 1/*
2 * Redistribution and use in source and binary forms, with or without
3 * modification, are permitted provided that the following conditions
4 * are met:
5 * 1. Redistributions of source code must retain the above copyright
6 * notice, this list of conditions and the following disclaimer.
7 * 2. Redistributions in binary form must reproduce the above copyright
8 * notice, this list of conditions and the following disclaimer in the
9 * documentation and/or other materials provided with the distribution.
10 *
11 * Jordan K. Hubbard
12 * 29 August 1998
13 *
|
14 * $Id: interp_parse.c,v 1.3 1998/09/04 02:43:26 msmith Exp $
| 14 * $Id: interp_parse.c,v 1.4 1998/09/17 23:52:02 msmith Exp $
|
15 *
16 * The meat of the simple parser.
17 */
18
19#include <stand.h>
20#include <string.h>
21
22/* Forward decls */
23extern char *backslash(char *str);
24
25static void clean(void);
26static int insert(int *argcp, char *buf);
27static char *variable_lookup(char *name);
28
29#define PARSE_BUFSIZE 1024 /* maximum size of one element */
30#define MAXARGS 20 /* maximum number of elements */
31static char *args[MAXARGS];
32
33/*
34 * parse: accept a string of input and "parse" it for backslash
35 * substitutions and environment variable expansions (${var}),
36 * returning an argc/argv style vector of whitespace separated
37 * arguments. Returns 0 on success, 1 on failure (ok, ok, so I
38 * wimped-out on the error codes! :).
39 *
40 * Note that the argv array returned must be freed by the caller, but
41 * we own the space allocated for arguments and will free that on next
42 * invocation. This allows argv consumers to modify the array if
43 * required.
44 *
45 * NB: environment variables that expand to more than one whitespace
46 * separated token will be returned as a single argv[] element, not
47 * split in turn. Expanded text is also immune to further backslash
48 * elimination or expansion since this is a one-pass, non-recursive
49 * parser. You didn't specify more than this so if you want more, ask
50 * me. - jkh
51 */
52
53#define PARSE_FAIL(expr) \
54if (expr) { \
55 printf("fail at line %d\n", __LINE__); \
56 clean(); \
57 free(copy); \
58 free(buf); \
59 return 1; \
60}
61
62/* Accept the usual delimiters for a variable, returning counterpart */
63static char
64isdelim(char ch)
65{
66 if (ch == '{')
67 return '}';
68 else if (ch == '(')
69 return ')';
70 return '\0';
71}
72
73static int
74isquote(char ch)
75{
76 return (ch == '\'' || ch == '"');
77}
78
79int
80parse(int *argc, char ***argv, char *str)
81{
82 int ac;
83 char *val, *p, *q, *copy = NULL;
84 int i = 0;
85 char token, tmp, quote, *buf;
86 enum { STR, VAR, WHITE } state;
87
88 ac = *argc = 0;
89 quote = 0;
90 if (!str || (p = copy = backslash(str)) == NULL)
91 return 1;
92
93 /* Initialize vector and state */
94 clean();
95 state = STR;
96 buf = (char *)malloc(PARSE_BUFSIZE);
97 token = 0;
98
99 /* And awaaaaaaaaay we go! */
100 while (*p) {
101 switch (state) {
102 case STR:
| 15 *
16 * The meat of the simple parser.
17 */
18
19#include <stand.h>
20#include <string.h>
21
22/* Forward decls */
23extern char *backslash(char *str);
24
25static void clean(void);
26static int insert(int *argcp, char *buf);
27static char *variable_lookup(char *name);
28
29#define PARSE_BUFSIZE 1024 /* maximum size of one element */
30#define MAXARGS 20 /* maximum number of elements */
31static char *args[MAXARGS];
32
33/*
34 * parse: accept a string of input and "parse" it for backslash
35 * substitutions and environment variable expansions (${var}),
36 * returning an argc/argv style vector of whitespace separated
37 * arguments. Returns 0 on success, 1 on failure (ok, ok, so I
38 * wimped-out on the error codes! :).
39 *
40 * Note that the argv array returned must be freed by the caller, but
41 * we own the space allocated for arguments and will free that on next
42 * invocation. This allows argv consumers to modify the array if
43 * required.
44 *
45 * NB: environment variables that expand to more than one whitespace
46 * separated token will be returned as a single argv[] element, not
47 * split in turn. Expanded text is also immune to further backslash
48 * elimination or expansion since this is a one-pass, non-recursive
49 * parser. You didn't specify more than this so if you want more, ask
50 * me. - jkh
51 */
52
53#define PARSE_FAIL(expr) \
54if (expr) { \
55 printf("fail at line %d\n", __LINE__); \
56 clean(); \
57 free(copy); \
58 free(buf); \
59 return 1; \
60}
61
62/* Accept the usual delimiters for a variable, returning counterpart */
63static char
64isdelim(char ch)
65{
66 if (ch == '{')
67 return '}';
68 else if (ch == '(')
69 return ')';
70 return '\0';
71}
72
73static int
74isquote(char ch)
75{
76 return (ch == '\'' || ch == '"');
77}
78
79int
80parse(int *argc, char ***argv, char *str)
81{
82 int ac;
83 char *val, *p, *q, *copy = NULL;
84 int i = 0;
85 char token, tmp, quote, *buf;
86 enum { STR, VAR, WHITE } state;
87
88 ac = *argc = 0;
89 quote = 0;
90 if (!str || (p = copy = backslash(str)) == NULL)
91 return 1;
92
93 /* Initialize vector and state */
94 clean();
95 state = STR;
96 buf = (char *)malloc(PARSE_BUFSIZE);
97 token = 0;
98
99 /* And awaaaaaaaaay we go! */
100 while (*p) {
101 switch (state) {
102 case STR:
|
103 if (isquote(*p)) {
| 103 if ((*p == '\\') && p[1]) {
104 p++;
105 PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
106 buf[i] = *p++;
107 } else if (isquote(*p)) {
|
104 quote = quote ? 0 : *p;
105 ++p;
106 }
107 else if (isspace(*p) && !quote) {
108 state = WHITE;
109 if (i) {
110 buf[i] = '\0';
111 PARSE_FAIL(insert(&ac, buf));
112 i = 0;
113 }
114 ++p;
115 } else if (*p == '$') {
116 token = isdelim(*(p + 1));
117 if (token)
118 p += 2;
119 else
120 ++p;
121 state = VAR;
122 } else {
123 PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
124 buf[i++] = *p++;
125 }
126 break;
127
128 case WHITE:
129 if (isspace(*p))
130 ++p;
131 else
132 state = STR;
133 break;
134
135 case VAR:
136 if (token) {
137 PARSE_FAIL((q = index(p, token)) == NULL);
138 } else {
139 q = p;
140 while (*q && !isspace(*q))
141 ++q;
142 }
143 tmp = *q;
144 *q = '\0';
145 if ((val = variable_lookup(p)) != NULL) {
146 int len = strlen(val);
147
148 strncpy(buf + i, val, PARSE_BUFSIZE - (i + 1));
149 i += min(len, PARSE_BUFSIZE - 1);
150 }
151 *q = tmp; /* restore value */
152 p = q + (token ? 1 : 0);
153 state = STR;
154 break;
155 }
156 }
157 /* If at end of token, add it */
158 if (i && state == STR) {
159 buf[i] = '\0';
160 PARSE_FAIL(insert(&ac, buf));
161 }
162 args[ac] = NULL;
163 *argc = ac;
164 *argv = (char **)malloc((sizeof(char *) * ac + 1));
165 bcopy(args, *argv, sizeof(char *) * ac + 1);
166 free(copy);
167 return 0;
168}
169
170#define MAXARGS 20
171
172/* Clean vector space */
173static void
174clean(void)
175{
176 int i;
177
178 for (i = 0; i < MAXARGS; i++) {
179 if (args[i] != NULL) {
180 free(args[i]);
181 args[i] = NULL;
182 }
183 }
184}
185
186static int
187insert(int *argcp, char *buf)
188{
189 if (*argcp >= MAXARGS)
190 return 1;
191 args[(*argcp)++] = strdup(buf);
192 return 0;
193}
194
195static char *
196variable_lookup(char *name)
197{
198 /* XXX search "special variable" space first? */
199 return (char *)getenv(name);
200}
| 108 quote = quote ? 0 : *p;
109 ++p;
110 }
111 else if (isspace(*p) && !quote) {
112 state = WHITE;
113 if (i) {
114 buf[i] = '\0';
115 PARSE_FAIL(insert(&ac, buf));
116 i = 0;
117 }
118 ++p;
119 } else if (*p == '$') {
120 token = isdelim(*(p + 1));
121 if (token)
122 p += 2;
123 else
124 ++p;
125 state = VAR;
126 } else {
127 PARSE_FAIL(i == (PARSE_BUFSIZE - 1));
128 buf[i++] = *p++;
129 }
130 break;
131
132 case WHITE:
133 if (isspace(*p))
134 ++p;
135 else
136 state = STR;
137 break;
138
139 case VAR:
140 if (token) {
141 PARSE_FAIL((q = index(p, token)) == NULL);
142 } else {
143 q = p;
144 while (*q && !isspace(*q))
145 ++q;
146 }
147 tmp = *q;
148 *q = '\0';
149 if ((val = variable_lookup(p)) != NULL) {
150 int len = strlen(val);
151
152 strncpy(buf + i, val, PARSE_BUFSIZE - (i + 1));
153 i += min(len, PARSE_BUFSIZE - 1);
154 }
155 *q = tmp; /* restore value */
156 p = q + (token ? 1 : 0);
157 state = STR;
158 break;
159 }
160 }
161 /* If at end of token, add it */
162 if (i && state == STR) {
163 buf[i] = '\0';
164 PARSE_FAIL(insert(&ac, buf));
165 }
166 args[ac] = NULL;
167 *argc = ac;
168 *argv = (char **)malloc((sizeof(char *) * ac + 1));
169 bcopy(args, *argv, sizeof(char *) * ac + 1);
170 free(copy);
171 return 0;
172}
173
174#define MAXARGS 20
175
176/* Clean vector space */
177static void
178clean(void)
179{
180 int i;
181
182 for (i = 0; i < MAXARGS; i++) {
183 if (args[i] != NULL) {
184 free(args[i]);
185 args[i] = NULL;
186 }
187 }
188}
189
190static int
191insert(int *argcp, char *buf)
192{
193 if (*argcp >= MAXARGS)
194 return 1;
195 args[(*argcp)++] = strdup(buf);
196 return 0;
197}
198
199static char *
200variable_lookup(char *name)
201{
202 /* XXX search "special variable" space first? */
203 return (char *)getenv(name);
204}
|