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- /* xxd.c - hexdump.
- *
- * Copyright 2015 The Android Open Source Project
- *
- * No obvious standard.
- * Regular output:
- * "00000000: 4c69 6e75 7820 7665 7273 696f 6e20 342e Linux version 4."
- * xxd -i "include" or "initializer" output:
- * " 0x4c, 0x69, 0x6e, 0x75, 0x78, 0x20, 0x76, 0x65, 0x72, 0x73, 0x69, 0x6f,"
- * xxd -p "plain" output:
- * "4c696e75782076657273696f6e20342e392e302d342d616d643634202864"
- USE_XXD(NEWTOY(xxd, ">1c#<0>256l#o#g#<1=2iprs#[!rs]", TOYFLAG_USR|TOYFLAG_BIN))
- config XXD
- bool "xxd"
- default y
- help
- usage: xxd [-c n] [-g n] [-i] [-l n] [-o n] [-p] [-r] [-s n] [file]
- Hexdump a file to stdout. If no file is listed, copy from stdin.
- Filename "-" is a synonym for stdin.
- -c n Show n bytes per line (default 16)
- -g n Group bytes by adding a ' ' every n bytes (default 2)
- -i Output include file (CSV hex bytes, plus C header/footer if not stdin)
- -l n Limit of n bytes before stopping (default is no limit)
- -o n Add n to display offset
- -p Plain hexdump (30 bytes/line, no grouping)
- -r Reverse operation: turn a hexdump into a binary file
- -s n Skip to offset n
- */
- #define FOR_xxd
- #include "toys.h"
- GLOBALS(
- long s, g, o, l, c;
- )
- static void do_xxd(int fd, char *name)
- {
- long long pos = 0;
- long long limit = TT.l;
- int i, len, space;
- if (FLAG(s)) {
- xlseek(fd, TT.s, SEEK_SET);
- pos = TT.s;
- if (limit) limit += TT.s;
- }
- while (0<(len = readall(fd, toybuf,
- (limit && limit-pos<TT.c)?limit-pos:TT.c)))
- {
- if (!FLAG(p)) printf("%08llx: ", TT.o + pos);
- pos += len;
- space = 2*TT.c+TT.c/TT.g+1;
- for (i=0; i<len;) {
- space -= printf("%02x", toybuf[i]);
- if (!(++i%TT.g)) {
- putchar(' ');
- space--;
- }
- }
- if (!FLAG(p)) {
- printf("%*s", space, "");
- for (i=0; i<len; i++)
- putchar((toybuf[i]>=' ' && toybuf[i]<='~') ? toybuf[i] : '.');
- }
- putchar('\n');
- }
- if (len<0) perror_exit("read");
- }
- static void do_xxd_include(int fd, char *name)
- {
- int c = 1, i, len;
- // The original xxd outputs a header/footer if given a filename (not stdin).
- // We don't, which means that unlike the original we can implement -ri.
- while ((len = read(fd, toybuf, sizeof(toybuf))) > 0) {
- for (i = 0; i < len; ++i) {
- printf("%s%#.02x", c > 1 ? ", " : " ", toybuf[i]);
- if (c++ == TT.c) {
- xprintf(",\n");
- c = 1;
- }
- }
- }
- if (len < 0) perror_msg_raw(name);
- if (c > 1) xputc('\n');
- }
- static int dehex(char ch)
- {
- if (ch >= '0' && ch <= '9') return ch - '0';
- if (ch >= 'a' && ch <= 'f') return ch - 'a' + 10;
- if (ch >= 'A' && ch <= 'F') return ch - 'A' + 10;
- return (ch == '\n') ? -2 : -1;
- }
- static void do_xxd_reverse(int fd, char *name)
- {
- FILE *fp = xfdopen(fd, "r");
- int tmp;
- // -ri is a very easy special case.
- if (FLAG(i)) while (fscanf(fp, " 0x%02x,", &tmp) == 1) xputc(tmp);
- else while (!feof(fp)) {
- int col = 0;
- // Each line of a regular hexdump starts with an offset/address.
- // Each line of a plain hexdump just goes straight into the bytes.
- if (!FLAG(p)) {
- long long pos;
- if (fscanf(fp, "%llx: ", &pos) == 1) {
- if (fseek(stdout, pos, SEEK_SET) != 0) {
- // TODO: just write out zeros if non-seekable?
- perror_exit("%s: seek failed", name);
- }
- }
- }
- // A plain hexdump can have as many bytes per line as you like,
- // but a non-plain hexdump assumes garbage after it's seen the
- // specified number of bytes.
- while (FLAG(p) || col < TT.c) {
- int n1, n2;
- // If we're at EOF or EOL or we read some non-hex...
- if ((n1 = n2 = dehex(fgetc(fp))) < 0 || (n2 = dehex(fgetc(fp))) < 0) {
- // If we're at EOL, start on that line.
- if (n1 == -2 || n2 == -2) continue;
- // Otherwise, skip to the next line.
- break;
- }
- fputc((n1 << 4) | (n2 & 0xf), stdout);
- col++;
- // Is there any grouping going on? Ignore a single space.
- tmp = fgetc(fp);
- if (tmp != ' ') ungetc(tmp, fp);
- }
- // Skip anything else on this line (such as the ASCII dump).
- while ((tmp = fgetc(fp)) != EOF && tmp != '\n');
- }
- if (ferror(fp)) perror_msg_raw(name);
- fclose(fp);
- }
- void xxd_main(void)
- {
- if (!TT.c) TT.c = FLAG(i) ? 12 : 16;
- // Plain style is 30 bytes/line, no grouping.
- if (FLAG(p)) TT.c = TT.g = 30;
- loopfiles(toys.optargs,
- FLAG(r) ? do_xxd_reverse : (FLAG(i) ? do_xxd_include : do_xxd));
- }
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