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1 /* cmp.c - Compare two files.
2  *
3  * Copyright 2012 Timothy Elliott <tle@holymonkey.com>
4  *
5  * See http://opengroup.org/onlinepubs/9699919799/utilities/cmp.html
6 
7 USE_CMP(NEWTOY(cmp, "<2>2ls[!ls]", TOYFLAG_USR|TOYFLAG_BIN))
8 
9 config CMP
10   bool "cmp"
11   default y
12   help
13     usage: cmp [-l] [-s] FILE1 FILE2
14 
15     Compare the contents of two files.
16 
17     -l	show all differing bytes
18     -s	silent
19 */
20 
21 #define FOR_cmp
22 #include "toys.h"
23 
GLOBALS(int fd;char * name;)24 GLOBALS(
25   int fd;
26   char *name;
27 )
28 
29 // This handles opening the file and
30 
31 static void do_cmp(int fd, char *name)
32 {
33   int i, len1, len2, min_len, size = sizeof(toybuf)/2;
34   long byte_no = 1, line_no = 1;
35   char *buf2 = toybuf+size;
36 
37   // First time through, cache the data and return.
38   if (!TT.fd) {
39     TT.name = name;
40     // On return the old filehandle is closed, and this assures that even
41     // if we were called with stdin closed, the new filehandle != 0.
42     TT.fd = dup(fd);
43     return;
44   }
45 
46   toys.exitval = 0;
47 
48   for (;;) {
49     len1 = readall(TT.fd, toybuf, size);
50     len2 = readall(fd, buf2, size);
51 
52     min_len = len1 < len2 ? len1 : len2;
53     for (i=0; i<min_len; i++) {
54       if (toybuf[i] != buf2[i]) {
55         toys.exitval = 1;
56         if (toys.optflags & FLAG_l)
57           printf("%ld %o %o\n", byte_no, toybuf[i], buf2[i]);
58         else {
59           if (!(toys.optflags & FLAG_s))
60             printf("%s %s differ: char %ld, line %ld\n",
61               TT.name, name, byte_no, line_no);
62           goto out;
63         }
64       }
65       byte_no++;
66       if (toybuf[i] == '\n') line_no++;
67     }
68     if (len1 != len2) {
69       if (!(toys.optflags & FLAG_s))
70         fprintf(stderr, "cmp: EOF on %s\n", len1 < len2 ? TT.name : name);
71       toys.exitval = 1;
72       break;
73     }
74     if (len1 < 1) break;
75   }
76 out:
77   if (CFG_TOYBOX_FREE) close(TT.fd);
78 }
79 
cmp_main(void)80 void cmp_main(void)
81 {
82   toys.exitval = 2;
83   loopfiles_rw(toys.optargs, O_CLOEXEC|(WARN_ONLY*!(toys.optflags&FLAG_s)), 0,
84     do_cmp);
85 }
86 
87