1 /*
2 This is a C version of the cmd/snappytool Go program.
3
4 To build the snappytool binary:
5 g++ main.cpp /usr/lib/libsnappy.a -o snappytool
6 or, if you have built the C++ snappy library from source:
7 g++ main.cpp /path/to/your/snappy/.libs/libsnappy.a -o snappytool
8 after running "make" from your snappy checkout directory.
9 */
10
11 #include <errno.h>
12 #include <stdio.h>
13 #include <string.h>
14 #include <unistd.h>
15
16 #include "snappy.h"
17
18 #define N 1000000
19
20 char dst[N];
21 char src[N];
22
main(int argc,char ** argv)23 int main(int argc, char** argv) {
24 // Parse args.
25 if (argc != 2) {
26 fprintf(stderr, "exactly one of -d or -e must be given\n");
27 return 1;
28 }
29 bool decode = strcmp(argv[1], "-d") == 0;
30 bool encode = strcmp(argv[1], "-e") == 0;
31 if (decode == encode) {
32 fprintf(stderr, "exactly one of -d or -e must be given\n");
33 return 1;
34 }
35
36 // Read all of stdin into src[:s].
37 size_t s = 0;
38 while (1) {
39 if (s == N) {
40 fprintf(stderr, "input too large\n");
41 return 1;
42 }
43 ssize_t n = read(0, src+s, N-s);
44 if (n == 0) {
45 break;
46 }
47 if (n < 0) {
48 fprintf(stderr, "read error: %s\n", strerror(errno));
49 // TODO: handle EAGAIN, EINTR?
50 return 1;
51 }
52 s += n;
53 }
54
55 // Encode or decode src[:s] to dst[:d], and write to stdout.
56 size_t d = 0;
57 if (encode) {
58 if (N < snappy::MaxCompressedLength(s)) {
59 fprintf(stderr, "input too large after encoding\n");
60 return 1;
61 }
62 snappy::RawCompress(src, s, dst, &d);
63 } else {
64 if (!snappy::GetUncompressedLength(src, s, &d)) {
65 fprintf(stderr, "could not get uncompressed length\n");
66 return 1;
67 }
68 if (N < d) {
69 fprintf(stderr, "input too large after decoding\n");
70 return 1;
71 }
72 if (!snappy::RawUncompress(src, s, dst)) {
73 fprintf(stderr, "input was not valid Snappy-compressed data\n");
74 return 1;
75 }
76 }
77 write(1, dst, d);
78 return 0;
79 }
80