111 lines
2.9 KiB
C
111 lines
2.9 KiB
C
/*
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* Ascii magic -- file types that we know based on keywords
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* that can appear anywhere in the file.
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*
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* Copyright (c) Ian F. Darwin, 1987.
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* Written by Ian F. Darwin.
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*
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* This software is not subject to any license of the American Telephone
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* and Telegraph Company or of the Regents of the University of California.
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*
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* Permission is granted to anyone to use this software for any purpose on
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* any computer system, and to alter it and redistribute it freely, subject
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* to the following restrictions:
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*
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* 1. The author is not responsible for the consequences of use of this
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* software, no matter how awful, even if they arise from flaws in it.
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*
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* 2. The origin of this software must not be misrepresented, either by
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* explicit claim or by omission. Since few users ever read sources,
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* credits must appear in the documentation.
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*
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* 3. Altered versions must be plainly marked as such, and must not be
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* misrepresented as being the original software. Since few users
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* ever read sources, credits must appear in the documentation.
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*
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* 4. This notice may not be removed or altered.
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*/
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#include <stdio.h>
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#include <ctype.h>
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#include "file.h"
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#include "names.h"
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#ifndef lint
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static char *moduleid =
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"@(#)$Header: /cvsroot/src/usr.bin/file/Attic/ascmagic.c,v 1.1.1.1 1993/03/21 09:45:37 cgd Exp $";
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#endif /* lint */
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char *ckfmsg = "write error on output";
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/* an optimisation over plain strcmp() */
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#define STREQ(a, b) (*(a) == *(b) && strcmp((a), (b)) == 0)
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ascmagic(buf)
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register char *buf;
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{
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register int i;
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char *s, *strtok(), *token;
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register struct names *p;
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extern int nbytes;
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short has_escapes = 0;
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/* these are easy, do them first */
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/*
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* for troff, look for . + letter + letter;
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* this must be done to disambiguate tar archives' ./file
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* and other trash from real troff input.
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*/
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if (*buf == '.' &&
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isascii(*(buf+1)) && isalnum(*(buf+1)) &&
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isascii(*(buf+2)) && isalnum(*(buf+2))){
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ckfputs("troff or preprocessor input text", stdout);
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return 1;
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}
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if ((*buf == 'c' || *buf == 'C') &&
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isascii(*(buf + 1)) && isspace(*(buf + 1))) {
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ckfputs("fortran program text", stdout);
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return 1;
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}
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/* look for tokens from names.h - this is expensive! */
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s = buf;
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while ((token = strtok(s, " \t\n\r\f")) != NULL) {
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s = NULL; /* make strtok() keep on tokin' */
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for (p = names; p < names + NNAMES; p++) {
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if (STREQ(p->name, token)) {
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ckfputs(types[p->type], stdout);
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return 1;
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}
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}
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}
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switch (is_tar(buf)) {
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case 1:
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ckfputs("tar archive", stdout);
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return 1;
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case 2:
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ckfputs("POSIX tar archive", stdout);
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return 1;
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}
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for (i = 0; i < nbytes; i++) {
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if (!isascii(*(buf+i)))
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return 0; /* not all ascii */
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if (*(buf+i) == '\033') /* ascii ESCAPE */
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has_escapes ++;
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}
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/* all else fails, but it is ascii... */
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if (has_escapes){
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ckfputs("ascii text (with escape sequences)", stdout);
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}
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else {
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ckfputs("ascii text", stdout);
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}
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return 1;
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}
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