1 #include	"mk.h"
2 
3 /*
4  *	This file contains functions that depend on the shell's syntax.  Most
5  *	of the routines extract strings observing the shell's escape conventions.
6  */
7 
8 
9 /*
10  *	skip a token in quotes.
11  */
12 static char *
13 squote(char *cp, int c)
14 {
15 	Rune r;
16 	int n;
17 
18 	while(*cp){
19 		n = chartorune(&r, cp);
20 		if(r == c)
21 			return cp;
22 		if(r == '\\')
23 			n += chartorune(&r, cp+n);
24 		cp += n;
25 	}
26 	SYNERR(-1);		/* should never occur */
27 	fprint(2, "missing closing '\n");
28 	return 0;
29 }
30 /*
31  *	search a string for unescaped characters in a pattern set
32  */
33 static char *
34 shcharin(char *cp, char *pat)
35 {
36 	Rune r;
37 	int n, vargen;
38 
39 	vargen = 0;
40 	while(*cp){
41 		n = chartorune(&r, cp);
42 		switch(r){
43 		case '\\':			/* skip escaped char */
44 			cp += n;
45 			n = chartorune(&r, cp);
46 			break;
47 		case '\'':			/* skip quoted string */
48 		case '"':
49 			cp = squote(cp+1, r);	/* n must = 1 */
50 			if(!cp)
51 				return 0;
52 			break;
53 		case '$':
54 			if(*(cp+1) == '{')
55 				vargen = 1;
56 			break;
57 		case '}':
58 			if(vargen)
59 				vargen = 0;
60 			else if(utfrune(pat, r))
61 				return cp;
62 			break;
63 		default:
64 			if(vargen == 0 && utfrune(pat, r))
65 				return cp;
66 			break;
67 		}
68 		cp += n;
69 	}
70 	if(vargen){
71 		SYNERR(-1);
72 		fprint(2, "missing closing } in pattern generator\n");
73 	}
74 	return 0;
75 }
76 
77 /*
78  *	extract an escaped token.  Possible escape chars are single-quote,
79  *	double-quote,and backslash.
80  */
81 static char*
82 shexpandquote(char *s, Rune esc, Bufblock *b)
83 {
84 	Rune r;
85 
86 	if (esc == '\\') {
87 		s += chartorune(&r, s);
88 		rinsert(b, r);
89 		return s;
90 	}
91 
92 	while(*s){
93 		s += chartorune(&r, s);
94 		if(r == esc)
95 			return s;
96 		if (r == '\\') {
97 			rinsert(b, r);
98 			s += chartorune(&r, s);
99 		}
100 		rinsert(b, r);
101 	}
102 	return 0;
103 }
104 
105 /*
106  *	Input an escaped token.  Possible escape chars are single-quote,
107  *	double-quote and backslash.
108  */
109 static int
110 shescapetoken(Biobuf *bp, Bufblock *buf, int preserve, int esc)
111 {
112 	int c, line;
113 
114 	if(esc == '\\') {
115 		c = Bgetrune(bp);
116 		if(c == '\r')
117 			c = Bgetrune(bp);
118 		if (c == '\n')
119 			mkinline++;
120 		rinsert(buf, c);
121 		return 1;
122 	}
123 
124 	line = mkinline;
125 	while((c = nextrune(bp, 0)) >= 0){
126 		if(c == esc){
127 			if(preserve)
128 				rinsert(buf, c);
129 			return 1;
130 		}
131 		if(c == '\\') {
132 			rinsert(buf, c);
133 			c = Bgetrune(bp);
134 			if(c == '\r')
135 				c = Bgetrune(bp);
136 			if (c < 0)
137 				break;
138 			if (c == '\n')
139 				mkinline++;
140 		}
141 		rinsert(buf, c);
142 	}
143 	SYNERR(line); fprint(2, "missing closing %c\n", esc);
144 	return 0;
145 }
146 
147 /*
148  *	copy a quoted string; s points to char after opening quote
149  */
150 static char *
151 copysingle(char *s, Rune q, Bufblock *buf)
152 {
153 	Rune r;
154 
155 	while(*s){
156 		s += chartorune(&r, s);
157 		rinsert(buf, r);
158 		if(r == q)
159 			break;
160 	}
161 	return s;
162 }
163 /*
164  *	check for quoted strings.  backquotes are handled here; single quotes above.
165  *	s points to char after opening quote, q.
166  */
167 static char *
168 shcopyq(char *s, Rune q, Bufblock *buf)
169 {
170 	if(q == '\'' || q == '"')		/* copy quoted string */
171 		return copysingle(s, q, buf);
172 
173 	if(q != '`')				/* not quoted */
174 		return s;
175 
176 	while(*s){				/* copy backquoted string */
177 		s += chartorune(&q, s);
178 		rinsert(buf, q);
179 		if(q == '`')
180 			break;
181 		if(q == '\'' || q == '"')
182 			s = copysingle(s, q, buf);	/* copy quoted string */
183 	}
184 	return s;
185 }
186 
187 static int
188 shmatchname(char *name)
189 {
190 	USED(name);
191 
192 	return 1;
193 }
194 
195 
196 Shell shshell = {
197 	"sh",
198 	"\"'= \t",	/*used in parse.c to isolate assignment attribute*/
199 	' ',	/* inter-word separator in env */
200 	shcharin,
201 	shexpandquote,
202 	shescapetoken,
203 	shcopyq,
204 	shmatchname
205 };