hgm@beta.UUCP (Harry McGavran) (06/09/87)
If you have trouble getting files from the news onto MINIX with
lines ending in spaces getting truncated, and perhaps other software
along they way compressing spaces into tabs, then you might want
the ehancements to the uudecode that Dr. Tanenbaum posted, that I did.
When this sort of thing occurs, the count on the line before the
"end" can be wrong. The DEC macro masks off the bottom six bits,
so the count can not be negative in the test for quitting the loop
in decode(). So I changed that as well. That might be considered a bug.
These enhancements expand tabs into spaces and fill out lines shortened
because they ended in blanks.
I also found it necessary to include a call to _cleanup(), or the file
ended up short. You may want to do that to uuencode as well.
As usual, I make no claims for the suitability of these changes for anything.
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/* uudecode - decode a uuencoded file */
/* call: uudecode [input_file] */
/* hgm - June 9, 1987 - added code to handle short lines and tabs */
#include "stdio.h"
#include "pwd.h"
#include "stat.h"
extern FILE *fopen();
char *fgets();
#define NULLF (FILE *) 0
#define NULLP (char *) 0
/* single character decode */
#define DEC(c) (((c) - ' ') & 077)
main(argc, argv)
char **argv;
{
FILE *in, *out;
struct stat sbuf;
int mode;
char dest[128];
char buf[80];
/* optional input arg */
if (argc > 1) {
if ((in = fopen(argv[1], "r")) == NULLF) {
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) == NULLP) {
fprintf(stderr, "No begin line\n");
exit(3);
}
if (strncmp(buf, "begin ", 6) == 0)
break;
}
sscanf(buf, "begin %o %s", &mode, dest);
/* handle ~user/file format */
if (dest[0] == '~') {
char *sl;
struct passwd *getpwnam();
char *index();
struct passwd *user;
char dnbuf[100];
sl = index(dest, '/');
if (sl == NULLP) {
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 == NULLF) {
perror(dest);
exit(4);
}
chmod(dest, mode);
decode(in, out);
if (fgets(buf, sizeof buf, in) == NULLP || strcmp(buf, "end\n")) {
fprintf(stderr, "No end line\n");
exit(5);
}
_cleanup();
exit(0);
}
/*
* copy from in to out, decoding as you go along.
*/
decode(in, out)
FILE *in;
FILE *out;
{
char tbuf[82];
char buf[82];
char *bp;
char *p;
int n;
int col;
for (;;) {
/* for each input line */
if (fgets(tbuf, sizeof tbuf, in) == NULLP) {
printf("Short file\n");
exit(10);
}
n = tbuf[0] - ' ';
if (n <= 0)
break;
/* expand tabs */
for (col = 0, p = tbuf; ((*p) && (*p != '\n') && (col < 78)); p++) {
if (*p == '\t') {
do {
buf[col++] = ' ';
} while (col % 8);
} else {
buf[col++] = *p;
}
}
/* fill with trailing blanks */
for (; ((col < (4*n + 1)) && (col < 78)); col++)
buf[col] = ' ';
buf[col++] = '\n';
buf[col] = '\0';
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);
}
/* fr: like read but stdio */
int
fr(fd, buf, cnt)
FILE *fd;
char *buf;
int cnt;
{
int c, i;
for (i=0; i<cnt; i++) {
c = getc(fd);
if (c == EOF)
return(i);
buf[i] = c;
}
return (cnt);
}
/*
* Return the ptr in sp at which the character c appears;
* NULL if not found
*/
char *
index(sp, c)
register char *sp, c;
{
do {
if (*sp == c)
return(sp);
} while (*sp++);
return(NULL);
}
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Harry G. McGavran, Jr.
Los Alamos National Laboratory
Group C-8, MS-B294
Los Alamos
New Mexico 87545
hgm@LANL.GOGO