Category : C Source Code
Archive   : SPLINT.ZIP
Filename : SPLINT.C

/* Splint:
* a data compression program
*
* This program refers the Pascal source codes of
* a splay-prefix encoding program in an article of
*
* Jones, Douglas. W,:
* Application of Splay Trees to Data Compression,
* Communications ACM, Vol. 31, No. 8, pp. 996 - 1007. (August 1988)
*
* Written by Kenji Rikitake and Naoshi Wakatabe.
* Copyright (C)1988, 1989 by Kenji Rikitake and Naoshi Wakatabe.
* All rights reserved.
* Permission to copy this program without fee all or part of this
* material is granted, provided that the copies are not made or
* distributed for direct commercial advantage.
*
* If you have any questions and/or suggestions, Contact
*
* Kenji Rikitake
* 4-19-11-102, Sakurajousui, Setagaya-ku,
* Tokyo 156 Japan
* JUNET: rikitake%[email protected]
*/
/* $Header: splint.cv 2.1 89/04/12 21:36:22 kenji Exp $
* $Log: RCS/splint.cv $
* Revision 2.1 89/04/12 21:36:22 kenji
* BSD filename bug fixed
*
* Revision 1.6 89/03/01 14:09:36 kenji
* Kenji welcome Naoshi one of the authors
*
* Revision 1.5 89/02/22 20:39:10 kenji
* Modified for Microsoft C 5.1 Small Model by Naoshi Wakatabe
*
* Revision 1.3 89/01/07 14:51:16 kenji
* unlink source file after successful conversion
*
* Revision 1.2 89/01/07 11:48:44 kenji
* now display RCS header
* decoding file existence check included
*
* Revision 1.1 89/01/06 23:47:40 kenji
* Initial revision
*
*/

static char *identfield = "$Header: splint.cv 2.1 89/04/12 21:36:22 kenji Exp $";


/* splint.c : encoding/decoding main program */

#include "splint.h"
#include "getopt.h"

#define MODE_UNDEF 0
#define DECODE_MODE 1
#define ENCODE_MODE 2

#define PWDLEN 64
#define FNAMLEN 32
#define MAGIC_1 0x93
#define MAGIC_2 0xB9

extern void spl_encode();
extern void spl_decode();

/* global variables */

static int encmode, verbose;
char spl_passwd[PWDLEN] = "";

/* encoding main routine */

void enc_file(orgname)
char *orgname;
{
static char splfile[FNAMLEN + 3], orgfile[FNAMLEN];
#if defined(MSDOS)
static char o_ext[_MAX_EXT];
static char dummy[_MAX_PATH];
#endif
#if defined(__TURBOC__)
static char o_ext[MAXEXT];
#endif
int i, j;
FILE *orgp, *splp;
struct stat statbuf;

/* make splayed filename in cwd */

#ifdef BSD
char *p;
if ((p = strrchr(orgname, '/')) != NULL) {
strcpy(orgfile, p);
}
else {
strcpy(orgfile, orgname);
}
/* add extension ".SP" if UNIX */
i = strlen(orgfile);
if (i > FNAMLEN) {
i = FNAMLEN;
}
for (j = 0; j < i; j++) {
splfile[j] = orgfile[j];
}
splfile[i] = '.';
splfile[i + 1] = 'S';
splfile[i + 2] = 'P';
splfile[i + 3] = '\0';
#ifdef DEBUG
fprintf(stderr, "%s, %s, %s\n", splfile, orgfile, orgname);
#endif
#endif

#ifdef __TURBOC__
/* change extension to ".spl" if MS-DOS */
fnsplit(orgname, NULL, NULL, orgfile, o_ext);
strcpy(splfile, orgfile);
strcat(orgfile, o_ext);
strcat(splfile, ".spl");
#endif
#ifdef MSDOS
/* change extension to ".spl" if MS-DOS(MSC) */
_splitpath(orgname, dummy, dummy, orgfile, o_ext);
strcpy(splfile, orgfile);
strcat(orgfile, o_ext);
strcat(splfile, ".spl");
#endif

/* check existence */
if (stat(splfile, &statbuf) == 0) {
char response[2];
response[0] = 'n';
fprintf(stderr, "splint: splayed file %s exists.\n", splfile);
fprintf(stderr, "Do you want to overwrite %s(Y/N)[N]? ", splfile);
fflush(stderr);
read(2, response, 2);
while (response[1] != '\n') {
if (read(2, response+1, 1) < 0) {
perror("stderr"); break;
}
}
if (response[0] != 'y') {
fprintf(stderr, "splint: %s not overwritten\n", splfile);
return;
}
}

/* open files */
#ifdef BSD
if((orgp = fopen(orgname, "r")) == NULL) {
fprintf(stderr, "splint: cannot open input file \"%s\" \n", orgname);
exit(-1);
}
if((splp = fopen(splfile, "w")) == NULL) {
fprintf(stderr, "splint: cannot open splay file \"%s\" \n", splfile);
exit(-1);
}
#endif
#if defined(__TURBOC__) || defined(MSDOS)
if((orgp = fopen(orgname, "rb")) == NULL) {
fprintf(stderr, "splint: cannot open input file \"%s\" \n", orgname);
exit(-1);
}
if((splp = fopen(splfile, "wb")) == NULL) {
fprintf(stderr, "splint: cannot open splay file \"%s\" \n", splfile);
exit(-1);
}
#endif

/* making a header */
putc(MAGIC_1, splp);
putc(MAGIC_2, splp);
putc(STYLE_ID, splp);
stat(orgname, &statbuf);
putc(statbuf.st_size & 0xff, splp);
putc((statbuf.st_size >> 8) & 0xff, splp);
putc((statbuf.st_size >> 16) & 0xff, splp);
putc((statbuf.st_size >> 24) & 0xff, splp);
fputs(orgfile, splp);
putc('\0', splp);

/* encoding */
rewind(orgp);
spl_encode(orgp, splp);

/* close files */
fclose(orgp);
fclose(splp);
/* delete original file */
unlink(orgname);

}

/* encoding main routine */

void dec_file(splname)
char *splname;
{
static char orgfile[FNAMLEN + 1];
int c, c1, c2, c3, i;
FILE *orgp, *splp;
struct stat statbuf;
long orgfsize;

/* open splayed file */

#ifdef BSD
if((splp = fopen(splname, "rb")) == NULL) {
fprintf(stderr, "splint: cannot open splay input file \"%s\" \n", splname);
exit(-1);
}
#endif
#if defined(__TURBOC__) || defined(MSDOS)
if((splp = fopen(splname, "rb")) == NULL) {
fprintf(stderr, "splint: cannot open splay input file \"%s\" \n", splname);
exit(-1);
}
#endif

/* check MAGIC numbers */
rewind(splp);
c1 = getc(splp);
c2 = getc(splp);
c3 = getc(splp);
if (c1 != MAGIC_1 || c2 != MAGIC_2 || c3 != STYLE_ID) {
fprintf(stderr, "splint: bad file - magic number error\n");
exit(-1);
}

/* get orgfile size */
c = getc(splp);
c1 = getc(splp);
c2 = getc(splp);
c3 = getc(splp);
orgfsize = ((long)c3 << 24) | ((long)c2 << 16) |
((long)c1 << 8) | (long)c;

/* get original filename */
i = 0;
while (1){
c = getc(splp);
orgfile[i] = c;
if (c == '\0') break;
i++;
if (i > FNAMLEN) {
fprintf(stderr, "splint: bad file - filename error\n");
exit(-1);
}
}

#ifdef DEBUG
fprintf(stderr, "filename = %s, length = %ld\n", orgfile, orgfsize);
#endif

/* check existence */
if (stat(orgfile, &statbuf) == 0) {
char response[2];
response[0] = 'n';
fprintf(stderr, "splint: original file %s exists.\n", orgfile);
fprintf(stderr, "Do you want to overwrite %s(Y/N)[N]? ", orgfile);
fflush(stderr);
read(2, response, 2);
while (response[1] != '\n') {
if (read(2, response+1, 1) < 0) {
perror("stderr"); break;
}
}
if (response[0] != 'y') {
fprintf(stderr, "splint: %s not overwritten\n", orgfile);
fclose(splp);
return;
}
}

/* open new original file */

#ifdef BSD
if((orgp = fopen(orgfile, "wb")) == NULL) {
fprintf(stderr, "splint: cannot open output file \"%s\" \n", orgfile);
exit(-1);
}
#endif
#if defined(__TURBOC__) || defined(MSDOS)
if((orgp = fopen(orgfile, "wb")) == NULL) {
fprintf(stderr, "splint: cannot open output file \"%s\" \n", orgfile);
exit(-1);
}
#endif

/* decoding */
spl_decode(splp, orgp);

/* close files */
fclose(orgp);
fclose(splp);

/* check file size */
stat(orgfile, &statbuf);
if (orgfsize == statbuf.st_size) {
unlink(splname);
}
else {
fprintf(stderr, "splint: decoded file %s has a wrong size, deleted\n", orgfile);
unlink(orgfile);
}
}

/* display usage */

static void usage()
{
fprintf(stderr,"Usage: splint -[deh] -g filename\n");
fprintf(stderr,"-h to help\n");
}

/* display help & copyright message */

static void disp_help()
{
fprintf(stderr,"Splint: a splay-prefix data compression program\n");
fprintf(stderr,"Beta release version\n");
fprintf(stderr,"$Header: splint.cv 2.1 89/04/12 21:36:22 kenji Exp $\n");
fprintf(stderr,"Copyright (c) 1988, 1989\n");
fprintf(stderr,"by Kenji Rikitake and Naoshi Wakatabe.\n");
fprintf(stderr,"All Rights Reserved.\n");
putc('\n', stderr);
usage();
fprintf(stderr," -d: decode from splayed file\n");
fprintf(stderr," -e: encode to splayed file\n");
fprintf(stderr," -g: encrypt/decrypt with following password\n");
fprintf(stderr," -h: display this help message\n");
putc('\n', stderr);
}

/* main routine */

int main(argc, argv)
int argc;
char *argv[];
{
int option;

encmode = MODE_UNDEF;

/* stdin = non-buffering keyboard */
setbuf(stdin, NULL);

/* parsing options */
while ((option = getopt(argc, argv, "deg:hv")) != EOF)
switch (option) {
case 'd':
encmode = DECODE_MODE;
break;
case 'e':
encmode = ENCODE_MODE;
break;
case 'g':
if (strlen(optarg) <= PWDLEN) {
strcpy(spl_passwd, optarg);
}
else {
fprintf(stderr, "splint: encrypt password too long\n");
usage();
exit(-1);
}
break;
case 'h':
disp_help();
exit(0);
break;
case '?':
usage();
exit(-1);
break;
default:
break;
}

if (encmode == MODE_UNDEF) {
fprintf(stderr, "splint: tell me what should I do\n");
usage();
exit(-1);
}

/* solve wildcarded filenames */

while (optind < argc) {
switch (encmode) {
case DECODE_MODE:
fprintf(stderr, "Decoding %s:\n", argv[optind]);
dec_file(argv[optind]);
break;
case ENCODE_MODE:
fprintf(stderr, "Encoding %s:\n", argv[optind]);
enc_file(argv[optind]);
break;
default:
fprintf(stderr, "splint: internal error in enc/dec loop\n");
exit(-1);
break;
}
optind++;
}

exit(0);
}