1 /*
2  * POSIX standard
3  *	test expression
4  *	[ expression ]
5  *
6  * Plan 9 additions:
7  *	-A file exists and is append-only
8  *	-L file exists and is exclusive-use
9  */
10 
11 #include <u.h>
12 #include <libc.h>
13 #define EQ(a,b)	((tmp=a)==0?0:(strcmp(tmp,b)==0))
14 
15 extern int isatty(int); /* <unistd.h> */
16 
17 int	ap;
18 int	ac;
19 char	**av;
20 char	*tmp;
21 
22 void	synbad(char *, char *);
23 int	fsizep(char *);
24 int	isdir(char *);
25 int	isreg(char *);
26 int	isint(char *, int *);
27 int	hasmode(char *, ulong);
28 int	tio(char *, int);
29 int	e(void), e1(void), e2(void), e3(void);
30 
31 void
32 main(int argc, char *argv[])
33 {
34 
35 	ac = argc; av = argv; ap = 1;
36 	if(EQ(argv[0],"[")) {
37 		if(!EQ(argv[--ac],"]"))
38 			synbad("] missing","");
39 	}
40 	argv[ac] = 0;
41 	if (ac<=1) exits("usage");
42 	exits(e()?0:"false");
43 }
44 
45 char *
46 nxtarg(int mt)
47 {
48 	if(ap>=ac){
49 		if(mt){
50 			ap++;
51 			return(0);
52 		}
53 		synbad("argument expected","");
54 	}
55 	return(av[ap++]);
56 }
57 
58 int
59 nxtintarg(int *pans)
60 {
61 	if(ap<ac && isint(av[ap], pans)){
62 		ap++;
63 		return 1;
64 	}
65 	return 0;
66 }
67 
68 int
69 e(void) {
70 	int p1;
71 
72 	p1 = e1();
73 	if (EQ(nxtarg(1), "-o")) return(p1 || e());
74 	ap--;
75 	return(p1);
76 }
77 
78 int
79 e1(void) {
80 	int p1;
81 
82 	p1 = e2();
83 	if (EQ(nxtarg(1), "-a")) return (p1 && e1());
84 	ap--;
85 	return(p1);
86 }
87 
88 int
89 e2(void) {
90 	if (EQ(nxtarg(0), "!"))
91 		return(!e2());
92 	ap--;
93 	return(e3());
94 }
95 
96 int
97 e3(void) {
98 	int p1;
99 	char *a;
100 	char *p2;
101 	int int1, int2;
102 
103 	a = nxtarg(0);
104 	if(EQ(a, "(")) {
105 		p1 = e();
106 		if(!EQ(nxtarg(0), ")")) synbad(") expected","");
107 		return(p1);
108 	}
109 
110 	if(EQ(a, "-A"))
111 		return(hasmode(nxtarg(0), DMAPPEND));
112 
113 	if(EQ(a, "-L"))
114 		return(hasmode(nxtarg(0), DMEXCL));
115 
116 	if(EQ(a, "-f"))
117 		return(isreg(nxtarg(0)));
118 
119 	if(EQ(a, "-d"))
120 		return(isdir(nxtarg(0)));
121 
122 	if(EQ(a, "-r"))
123 		return(tio(nxtarg(0), 4));
124 
125 	if(EQ(a, "-w"))
126 		return(tio(nxtarg(0), 2));
127 
128 	if(EQ(a, "-x"))
129 		return(tio(nxtarg(0), 1));
130 
131 	if(EQ(a, "-e"))
132 		return(tio(nxtarg(0), 0));
133 
134 	if(EQ(a, "-c"))
135 		return(0);
136 
137 	if(EQ(a, "-b"))
138 		return(0);
139 
140 	if(EQ(a, "-u"))
141 		return(0);
142 
143 	if(EQ(a, "-g"))
144 		return(0);
145 
146 	if(EQ(a, "-s"))
147 		return(fsizep(nxtarg(0)));
148 
149 	if(EQ(a, "-t"))
150 		if(ap>=ac || !nxtintarg(&int1))
151 			return(isatty(1));
152 		else
153 			return(isatty(int1));
154 
155 	if(EQ(a, "-n"))
156 		return(!EQ(nxtarg(0), ""));
157 	if(EQ(a, "-z"))
158 		return(EQ(nxtarg(0), ""));
159 
160 	p2 = nxtarg(1);
161 	if (p2==0)
162 		return(!EQ(a,""));
163 	if(EQ(p2, "="))
164 		return(EQ(nxtarg(0), a));
165 
166 	if(EQ(p2, "!="))
167 		return(!EQ(nxtarg(0), a));
168 
169 	if(!isint(a, &int1))
170 		return(!EQ(a,""));
171 
172 	if(nxtintarg(&int2)){
173 		if(EQ(p2, "-eq"))
174 			return(int1==int2);
175 		if(EQ(p2, "-ne"))
176 			return(int1!=int2);
177 		if(EQ(p2, "-gt"))
178 			return(int1>int2);
179 		if(EQ(p2, "-lt"))
180 			return(int1<int2);
181 		if(EQ(p2, "-ge"))
182 			return(int1>=int2);
183 		if(EQ(p2, "-le"))
184 			return(int1<=int2);
185 	}
186 
187 	synbad("unknown operator ",p2);
188 	return 0;		/* to shut ken up */
189 }
190 
191 int
192 tio(char *a, int f)
193 {
194 	return access (a, f) >= 0;
195 }
196 
197 /* copy to local memory; clear names for safety */
198 int
199 localstat(char *f, Dir *dir)
200 {
201 	Dir *d;
202 
203 	d = dirstat(f);
204 	if(d == 0)
205 		return(-1);
206 	*dir = *d;
207 	dir->name = 0;
208 	dir->uid = 0;
209 	dir->gid = 0;
210 	dir->muid = 0;
211 	return 0;
212 }
213 
214 /* copy to local memory; clear names for safety */
215 int
216 localfstat(int f, Dir *dir)
217 {
218 	Dir *d;
219 
220 	d = dirfstat(f);
221 	if(d == 0)
222 		return(-1);
223 	*dir = *d;
224 	dir->name = 0;
225 	dir->uid = 0;
226 	dir->gid = 0;
227 	dir->muid = 0;
228 	return 0;
229 }
230 
231 int
232 hasmode(char *f, ulong m)
233 {
234 	Dir dir;
235 
236 	if(localstat(f,&dir)<0)
237 		return(0);
238 	return(dir.mode&m);
239 }
240 
241 int
242 isdir(char *f)
243 {
244 	Dir dir;
245 
246 	if(localstat(f,&dir)<0)
247 		return(0);
248 	return(dir.mode&DMDIR);
249 }
250 
251 int
252 isreg(char *f)
253 {
254 	Dir dir;
255 
256 	if(localstat(f,&dir)<0)
257 		return(0);
258 	return(!(dir.mode&DMDIR));
259 }
260 
261 int
262 fsizep(char *f)
263 {
264 	Dir dir;
265 
266 	if(localstat(f,&dir)<0)
267 		return(0);
268 	return(dir.length>0);
269 }
270 
271 void
272 synbad(char *s1, char *s2)
273 {
274 	int len;
275 
276 	write(2, "test: ", 6);
277 	if ((len = strlen(s1)) != 0)
278 		write(2, s1, len);
279 	if ((len = strlen(s2)) != 0)
280 		write(2, s2, len);
281 	write(2, "\n", 1);
282 	exits("bad syntax");
283 }
284 
285 int
286 isint(char *s, int *pans)
287 {
288 	char *ep;
289 
290 	*pans = strtol(s, &ep, 0);
291 	return (*ep == 0);
292 }