notnotdnethack/sys/share/uudecode.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/*
 * Modified 12 April 1990 by Mark Adler for use on MSDOS systems with
 * Microsoft C and Turbo C.
 *
 * Modifed 13 February 1991 by Greg Roelofs for use on VMS systems.  As
 * with the MS-DOS version, the setting of the file mode has been disabled.
 * Compile and link normally (but note that the shared-image link option
 * produces a binary only 6 blocks long, as opposed to the 137-block one
 * produced by an ordinary link).  To set up the VMS symbol to run the
 * program ("run uudecode filename" won't work), do:
 *		uudecode :== "$disk:[directory]uudecode.exe"
 * and don't forget the leading "$" or it still won't work.  The binaries
 * produced by this program are in VMS "stream-LF" format; this makes no
 * difference to VMS when running decoded executables, nor to VMS unzip,
 * but other programs such as zoo or arc may or may not require the file
 * to be "BILFed" (or "unBILFed" or whatever).  Also, unlike the other
 * flavors, VMS files don't get overwritten (a higher version is created).
 * 
 * Modified 13 April 1991 by Gary Mussar to be forgiving of systems that
 * appear to be stripping trailing blanks.
 *
 * Modified 28 February 2002 for use on WIN32 systems with Microsoft C.
 */

#ifndef lint
static char sccsid[] = "@(#)uudecode.c	5.5 (Berkeley) 7/6/88";
#endif /* not lint */



/*
 * uudecode [input]
 *
 * create the specified file, decoding as you go.
 * used with uuencode.
 */
#include <stdio.h>

#    include <pwd.h>
#  include <sys/types.h>   /* MSDOS, WIN32, or UNIX */
#  include <sys/stat.h>
#  include <string.h>
#  include <stdlib.h>

static void decode(FILE *, FILE *);
static void outdec(char *, FILE *, int);

/* single-character decode */
#define DEC(c)	(((c) - ' ') & 077)

int
main(int argc, char **argv)
{
	FILE *in, *out;
	int mode;
	char dest[128];
	char buf[80];

	/* optional input arg */
	if (argc > 1) {
		if ((in = fopen(argv[1], "r")) == NULL) {
			perror(argv[1]);
			exit(1);
		}
		argv++; argc--;
	} else
		in = stdin;

	if (argc != 1) {
		printf("Usage: uudecode [infile]\n");
		exit(2);
	}

	/* search for header line */
	for (;;) {
		if (fgets(buf, sizeof buf, in) == NULL) {
			fprintf(stderr, "No begin line\n");
			exit(3);
		}
		if (strncmp(buf, "begin ", 6) == 0)
			break;
	}
	(void)sscanf(buf, "begin %o %s", &mode, dest);

	/* handle ~user/file format */
	if (dest[0] == '~') {
		char *sl;
		struct passwd *getpwnam();
		struct passwd *user;
		char dnbuf[100], *index(), *strcat(), *strcpy();

		sl = index(dest, '/');
		if (sl == NULL) {
			fprintf(stderr, "Illegal ~user\n");
			exit(3);
		}
		*sl++ = 0;
		user = getpwnam(dest+1);
		if (user == NULL) {
			fprintf(stderr, "No such user as %s\n", dest);
			exit(4);
		}
		strcpy(dnbuf, user->pw_dir);
		strcat(dnbuf, "/");
		strcat(dnbuf, sl);
		strcpy(dest, dnbuf);
	}

	/* create output file */
	out = fopen(dest, "w");
	if (out == NULL) {
		perror(dest);
		exit(4);
	}
	chmod(dest, mode);

	decode(in, out);

	if (fgets(buf, sizeof buf, in) == NULL || strcmp(buf, "end\n")) {
		fprintf(stderr, "No end line\n");
		exit(5);
	}
	exit(0);
	/*NOTREACHED*/
	return 0;
}

/*
 * copy from in to out, decoding as you go along.
 */
void
decode(in, out)
FILE *in;
FILE *out;
{
	char buf[80];
	char *bp;
	int n, i, expected;

	for (;;) {
		/* for each input line */
		if (fgets(buf, sizeof buf, in) == NULL) {
			printf("Short file\n");
			exit(10);
		}
		n = DEC(buf[0]);
		if ((n <= 0) || (buf[0] == '\n'))
			break;

		/* Calculate expected # of chars and pad if necessary */
		expected = ((n+2)/3)<<2;
		for (i = strlen(buf)-1; i <= expected; i++) buf[i] = ' ';

		bp = &buf[1];
		while (n > 0) {
			outdec(bp, out, n);
			bp += 4;
			n -= 3;
		}
	}
}

/*
 * output a group of 3 bytes (4 input characters).
 * the input chars are pointed to by p, they are to
 * be output to file f.  n is used to tell us not to
 * output all of them at the end of the file.
 */
void
outdec(p, f, n)
char *p;
FILE *f;
int n;
{
	int c1, c2, c3;

	c1 = DEC(*p) << 2 | DEC(p[1]) >> 4;
	c2 = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
	c3 = DEC(p[2]) << 6 | DEC(p[3]);
	if (n >= 1)
		putc(c1, f);
	if (n >= 2)
		putc(c2, f);
	if (n >= 3)
		putc(c3, f);
}

/*
 * Return the ptr in sp at which the character c appears;
 * NULL if not found
 */

#ifndef NULL
#define	NULL	0
#endif

char *
index(register char *sp, register char c)
{
	do {
		if (*sp == c)
			return(sp);
	} while (*sp++);
	return(NULL);
}