/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* 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.                                                     *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#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 "V.h"
#include "sys_pwd.h"
#include "sys_stat.h"
#include "sys_string.h"

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

main(argc, argv)
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];
/*		char *index(); */
/*		char *strcat(); */
/*		char *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);
}
/*
* copy from in to out, decoding as you go along.
*/
decode(in, out)
FILE *in;
FILE *out;
{
	char buf[80];
	char *bp;
	int n;

	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)
			break;
		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.
*/
outdec(p, f, n)
char *p;
FILE *f;
{
	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);
}