1 #include <u.h>
2 #include <libc.h>
3 #include <bio.h>
4 #include "diff.h"
5 
6 #define	DIRECTORY(s)		((s)->qid.type&QTDIR)
7 #define	REGULAR_FILE(s)		((s)->type == 'M' && !DIRECTORY(s))
8 
9 Biobuf	stdout;
10 
11 static char *tmp[] = {"/tmp/diff1", "/tmp/diff2"};
12 static int whichtmp;
13 static char *progname;
14 static char usage[] = "diff [ -efmnbwr ] file1 ... file2\n";
15 
16 static void
17 rmtmpfiles(void)
18 {
19 	while (whichtmp > 0) {
20 		whichtmp--;
21 		remove(tmp[whichtmp]);
22 	}
23 }
24 
25 void	
26 done(int status)
27 {
28 	rmtmpfiles();
29 Bflush(&stdout);
30 Bterm(&stdout);
31 	switch(status)
32 	{
33 	case 0:
34 		exits("");
35 	case 1:
36 		exits("some");
37 	default:
38 		exits("error");
39 	}
40 	/*NOTREACHED*/
41 }
42 
43 void
44 panic(int status, char *fmt, ...)
45 {
46 	va_list arg;
47 
48 	Bflush(&stdout);
49 
50 	fprint(2, "%s: ", progname);
51 	va_start(arg, fmt);
52 	vfprint(2, fmt, arg);
53 	va_end(arg);
54 	if (status)
55 		done(status);
56 		/*NOTREACHED*/
57 }
58 
59 static int
60 catch(void *a, char *msg)
61 {
62 	USED(a);
63 	panic(2, msg);
64 	return 1;
65 }
66 
67 int
68 mkpathname(char *pathname, char *path, char *name)
69 {
70 	if (strlen(path) + strlen(name) > MAXPATHLEN) {
71 		panic(0, "pathname %s/%s too long\n", path, name);
72 		return 1;
73 	}
74 	sprint(pathname, "%s/%s", path, name);
75 	return 0;
76 }
77 	
78 static char *
79 mktmpfile(int input, Dir **sb)
80 {
81 	int fd, i;
82 	char *p;
83 	char buf[8192];
84 
85 	atnotify(catch, 1);
86 	p = tmp[whichtmp++];
87 	fd = create(p, OWRITE, 0600);
88 	if (fd < 0) {
89 		panic(mflag ? 0: 2, "cannot create %s: %r\n", p);
90 		return 0;
91 	}
92 	while ((i = read(input, buf, sizeof(buf))) > 0) {
93 		if ((i = write(fd, buf, i)) < 0)
94 			break;
95 	}
96 	*sb = dirfstat(fd);
97 	close(fd);
98 	if (i < 0) {
99 		panic(mflag ? 0: 2, "cannot read/write %s: %r\n", p);
100 		return 0;
101 	}
102 	return p;
103 }
104 
105 static char *
106 statfile(char *file, Dir **sb)
107 {
108 	Dir *dir;
109 	int input;
110 
111 	dir = dirstat(file);
112 	if(dir == nil) {
113 		if (strcmp(file, "-") || (dir = dirfstat(0)) == nil) {
114 			panic(mflag ? 0: 2, "cannot stat %s: %r\n", file);
115 			return 0;
116 		}
117 		free(dir);
118 		return mktmpfile(0, sb);
119 	}
120 	else if (!REGULAR_FILE(dir) && !DIRECTORY(dir)) {
121 		free(dir);
122 		if ((input = open(file, OREAD)) == -1) {
123 			panic(mflag ? 0: 2, "cannot open %s: %r\n", file);
124 			return 0;
125 		}
126 		file = mktmpfile(input, sb);
127 		close(input);
128 	}
129 	else
130 		*sb = dir;
131 	return file;
132 }
133 
134 void
135 diff(char *f, char *t, int level)
136 {
137 	char *fp, *tp, *p, fb[MAXPATHLEN+1], tb[MAXPATHLEN+1];
138 	Dir *fsb, *tsb;
139 
140 	if ((fp = statfile(f, &fsb)) == 0)
141 		goto Return;
142 	if ((tp = statfile(t, &tsb)) == 0){
143 		free(fsb);
144 		goto Return;
145 	}
146 	if (DIRECTORY(fsb) && DIRECTORY(tsb)) {
147 		if (rflag || level == 0)
148 			diffdir(fp, tp, level);
149 		else
150 			Bprint(&stdout, "Common subdirectories: %s and %s\n",
151 				fp, tp);
152 	}
153 	else if (REGULAR_FILE(fsb) && REGULAR_FILE(tsb))
154 		diffreg(fp, tp);
155 	else {
156 		if (REGULAR_FILE(fsb)) {
157 			if ((p = utfrrune(f, '/')) == 0)
158 				p = f;
159 			else
160 				p++;
161 			if (mkpathname(tb, tp, p) == 0)
162 				diffreg(fp, tb);
163 		}
164 		else {
165 			if ((p = utfrrune(t, '/')) == 0)
166 				p = t;
167 			else
168 				p++;
169 			if (mkpathname(fb, fp, p) == 0)
170 				diffreg(fb, tp);
171 		}
172 	}
173 	free(fsb);
174 	free(tsb);
175 
176 Return:
177 	rmtmpfiles();
178 }
179 
180 void
181 main(int argc, char *argv[])
182 {
183 	char *p;
184 	int i;
185 	Dir *fsb, *tsb;
186 
187 	Binit(&stdout, 1, OWRITE);
188 	progname = *argv;
189 	while (--argc && (*++argv)[0] == '-' && (*argv)[1]) {
190 		for (p = *argv+1; *p; p++) {
191 			switch (*p) {
192 			case 'c':
193 			case 'e':
194 			case 'f':
195 			case 'n':
196 				mode = *p;
197 				break;
198 
199 			case 'w':
200 				bflag = 2;
201 				break;
202 
203 			case 'b':
204 				bflag = 1;
205 				break;
206 
207 			case 'r':
208 				rflag = 1;
209 				break;
210 
211 			case 'm':
212 				mflag = 1;	
213 				break;
214 
215 			case 'h':
216 			default:
217 				progname = "Usage";
218 				panic(2, usage);
219 			}
220 		}
221 	}
222 	if (argc < 2)
223 		panic(2, usage, progname);
224 	if ((tsb = dirstat(argv[argc-1])) == nil)
225 		panic(2, "can't stat %s\n", argv[argc-1]);
226 	if (argc > 2) {
227 		if (!DIRECTORY(tsb))
228 			panic(2, usage, progname);
229 		mflag = 1;
230 	}
231 	else {
232 		if ((fsb = dirstat(argv[0])) == nil)
233 			panic(2, "can't stat %s\n", argv[0]);
234 		if (DIRECTORY(fsb) && DIRECTORY(tsb))
235 			mflag = 1;
236 		free(fsb);
237 	}
238 	free(tsb);
239 	for (i = 0; i < argc-1; i++)
240 		diff(argv[i], argv[argc-1], 0);
241 
242 	done(anychange);
243 	/*NOTREACHED*/
244 }
245 
246 static char noroom[] = "out of memory - try diff -h\n";
247 
248 void *
249 emalloc(unsigned n)
250 {
251 	register void *p;
252 
253 	if ((p = malloc(n)) == 0)
254 		panic(2, noroom);
255 	return p;
256 }
257 
258 void *
259 erealloc(void *p, unsigned n)
260 {
261 	register void *rp;
262 
263 	if ((rp = realloc(p, n)) == 0)
264 		panic(2, noroom);
265 	return rp;
266 }