89 lines
2.3 KiB
C
89 lines
2.3 KiB
C
/*strings.c - print the strings of printable characters in files.
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*
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* Copyright 2014 Kyung-su Kim <kaspyx@gmail.com>
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* Copyright 2014 Kyungwan Han <asura321@gmail.com>
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*
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* See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/strings.html
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*
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* Deviations from posix: we don't readahead to the end of the string to see
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* if it ends with NUL or newline before printing. Add -o. We always do -a
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* (and accept but don't document the flag), but that's sort of conformant.
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* Posix' STDOUT section says things like "%o %s" and we support 64 bit offsets.
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*
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* TODO: utf8 strings
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USE_STRINGS(NEWTOY(strings, "t:an#=4<1fo", TOYFLAG_USR|TOYFLAG_BIN))
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config STRINGS
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bool "strings"
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default y
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help
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usage: strings [-fo] [-t oxd] [-n LEN] [FILE...]
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Display printable strings in a binary file
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-f Show filename
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-n At least LEN characters form a string (default 4)
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-o Show offset (ala -t d)
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-t Show offset type (o=octal, d=decimal, x=hexadecimal)
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*/
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#define FOR_strings
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#include "toys.h"
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GLOBALS(
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long n;
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char *t;
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)
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static void do_strings(int fd, char *filename)
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{
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int nread, i, wlen = TT.n, count = 0;
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off_t offset = 0;
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char *string = 0, pattern[8];
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if (TT.t) if (!(string = strchr("oxd", *TT.t))) error_exit("-t needs oxd");
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sprintf(pattern, "%%7ll%c ", string ? *string : 'd');
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// input buffer can wrap before we have enough data to output, so
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// copy start of string to temporary buffer until enough to output
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string = xzalloc(wlen+1);
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for (i = nread = 0; ;i++) {
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if (i >= nread) {
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nread = read(fd, toybuf, sizeof(toybuf));
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i = 0;
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if (nread < 0) perror_msg_raw(filename);
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if (nread < 1) {
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if (count) goto flush;
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break;
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}
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}
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offset++;
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if ((toybuf[i]>=32 && toybuf[i]<=126) || toybuf[i]=='\t') {
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if (count == wlen) fputc(toybuf[i], stdout);
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else {
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string[count++] = toybuf[i];
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if (count == wlen) {
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if (FLAG(f)) printf("%s: ", filename);
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if (FLAG(o) || FLAG(t)) printf(pattern, (long long)(offset - wlen));
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printf("%s", string);
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}
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}
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continue;
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}
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flush:
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// End of previous string
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if (count == wlen) xputc('\n');
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count = 0;
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}
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xclose(fd);
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free(string);
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}
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void strings_main(void)
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{
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loopfiles(toys.optargs, do_strings);
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}
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