1 /* xxd.c - hexdump.
2 *
3 * Copyright 2015 The Android Open Source Project
4 *
5 * No obvious standard.
6 * Regular output:
7 * "00000000: 4c69 6e75 7820 7665 7273 696f 6e20 342e Linux version 4."
8 * xxd -i "include" or "initializer" output:
9 * " 0x4c, 0x69, 0x6e, 0x75, 0x78, 0x20, 0x76, 0x65, 0x72, 0x73, 0x69, 0x6f,"
10 * xxd -p "plain" output:
11 * "4c696e75782076657273696f6e20342e392e302d342d616d643634202864"
12
13 USE_XXD(NEWTOY(xxd, ">1c#l#o#g#<1=2iprs#[!rs]", TOYFLAG_USR|TOYFLAG_BIN))
14
15 config XXD
16 bool "xxd"
17 default y
18 help
19 usage: xxd [-c n] [-g n] [-i] [-l n] [-o n] [-p] [-r] [-s n] [file]
20
21 Hexdump a file to stdout. If no file is listed, copy from stdin.
22 Filename "-" is a synonym for stdin.
23
24 -c n Show n bytes per line (default 16)
25 -g n Group bytes by adding a ' ' every n bytes (default 2)
26 -i Include file output format (comma-separated hex byte literals)
27 -l n Limit of n bytes before stopping (default is no limit)
28 -o n Add n to display offset
29 -p Plain hexdump (30 bytes/line, no grouping)
30 -r Reverse operation: turn a hexdump into a binary file
31 -s n Skip to offset n
32 */
33
34 #define FOR_xxd
35 #include "toys.h"
36
GLOBALS(long s,g,o,l,c;)37 GLOBALS(
38 long s, g, o, l, c;
39 )
40
41 static void do_xxd(int fd, char *name)
42 {
43 long long pos = 0;
44 long long limit = TT.l;
45 int i, len, space;
46
47 if (toys.optflags&FLAG_s) {
48 xlseek(fd, TT.s, SEEK_SET);
49 pos = TT.s;
50 if (limit) limit += TT.s;
51 }
52
53 while (0<(len = readall(fd, toybuf,
54 (limit && limit-pos<TT.c)?limit-pos:TT.c))) {
55 if (!(toys.optflags&FLAG_p)) printf("%08llx: ", TT.o + pos);
56 pos += len;
57 space = 2*TT.c+TT.c/TT.g+1;
58
59 for (i=0; i<len;) {
60 space -= printf("%02x", toybuf[i]);
61 if (!(++i%TT.g)) {
62 putchar(' ');
63 space--;
64 }
65 }
66
67 if (!(toys.optflags&FLAG_p)) {
68 printf("%*s", space, "");
69 for (i=0; i<len; i++)
70 putchar((toybuf[i]>=' ' && toybuf[i]<='~') ? toybuf[i] : '.');
71 }
72 putchar('\n');
73 }
74 if (len<0) perror_exit("read");
75 }
76
do_xxd_include(int fd,char * name)77 static void do_xxd_include(int fd, char *name)
78 {
79 long long total = 0;
80 int c = 1, i, len;
81
82 // The original xxd outputs a header/footer if given a filename (not stdin).
83 // We don't, which means that unlike the original we can implement -ri.
84 while ((len = read(fd, toybuf, sizeof(toybuf))) > 0) {
85 total += len;
86 for (i = 0; i < len; ++i) {
87 printf("%s%#.02x", c > 1 ? ", " : " ", toybuf[i]);
88 if (c++ == TT.c) {
89 xprintf(",\n");
90 c = 1;
91 }
92 }
93 }
94 if (len < 0) perror_msg_raw(name);
95 if (c > 1) xputc('\n');
96 }
97
dehex(char ch)98 static int dehex(char ch)
99 {
100 if (ch >= '0' && ch <= '9') return ch - '0';
101 if (ch >= 'a' && ch <= 'f') return ch - 'a' + 10;
102 if (ch >= 'A' && ch <= 'F') return ch - 'A' + 10;
103 return (ch == '\n') ? -2 : -1;
104 }
105
do_xxd_reverse(int fd,char * name)106 static void do_xxd_reverse(int fd, char *name)
107 {
108 #ifdef TOYBOX_OH_ADAPT
109 int dupFd = dup(fd);
110 if (dupFd < 0) {
111 perror_exit("%s: dup failed", name);
112 }
113 FILE *fp = xfdopen(dupFd, "r");
114 #else
115 FILE *fp = xfdopen(fd, "r");
116 #endif
117 int tmp;
118
119 if (toys.optflags&FLAG_i) {
120 // -ri is a very easy special case.
121 while (fscanf(fp, " 0x%02x,", &tmp) == 1) {
122 fputc(tmp & 0xff, stdout);
123 }
124 } else {
125 while (!feof(fp)) {
126 int col = 0;
127
128 // Each line of a regular hexdump starts with an offset/address.
129 // Each line of a plain hexdump just goes straight into the bytes.
130 if (!(toys.optflags&FLAG_p)) {
131 long long pos;
132
133 if (fscanf(fp, "%llx: ", &pos) == 1) {
134 if (fseek(stdout, pos, SEEK_SET) != 0) {
135 // TODO: just write out zeros if non-seekable?
136 perror_exit("%s: seek failed", name);
137 }
138 }
139 }
140
141 // A plain hexdump can have as many bytes per line as you like,
142 // but a non-plain hexdump assumes garbage after it's seen the
143 // specified number of bytes.
144 while (toys.optflags&FLAG_p || col < TT.c) {
145 int n1, n2;
146
147 // If we're at EOF or EOL or we read some non-hex...
148 if ((n1 = n2 = dehex(fgetc(fp))) < 0 || (n2 = dehex(fgetc(fp))) < 0) {
149 // If we're at EOL, start on that line.
150 if (n1 == -2 || n2 == -2) continue;
151 // Otherwise, skip to the next line.
152 break;
153 }
154
155 fputc((n1 << 4) | (n2 & 0xf), stdout);
156 col++;
157
158 // Is there any grouping going on? Ignore a single space.
159 tmp = fgetc(fp);
160 if (tmp != ' ') ungetc(tmp, fp);
161 }
162
163 // Skip anything else on this line (such as the ASCII dump).
164 while ((tmp = fgetc(fp)) != EOF && tmp != '\n')
165 ;
166 }
167 }
168
169 if (ferror(fp)) perror_msg_raw(name);
170 fclose(fp);
171 }
172
xxd_main(void)173 void xxd_main(void)
174 {
175 if (TT.c < 0 || TT.c > 256) error_exit("invalid -c: %ld", TT.c);
176 if (TT.c == 0) TT.c = (toys.optflags&FLAG_i)?12:16;
177
178 // Plain style is 30 bytes/line, no grouping.
179 if (toys.optflags&FLAG_p) TT.c = TT.g = 30;
180
181 loopfiles(toys.optargs,
182 toys.optflags&FLAG_r ? do_xxd_reverse
183 : (toys.optflags&FLAG_i ? do_xxd_include : do_xxd));
184 }
185