mmencode.c
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上传日期:2018-12-24
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- /*
- a lite version of mmencode, this version ONLY can be base64
- encodeing/decodeing
- Copyright (c) 1999 BBS Express Project.
- */
- /*
- CVS: $Id: mmencode.c,v 1.1 2000/01/15 01:45:32 edwardc Exp $
- */
- /*
- Copyright (c) 1991 Bell Communications Research, Inc. (Bellcore)
- Permission to use, copy, modify, and distribute this material
- for any purpose and without fee is hereby granted, provided
- that the above copyright notice and this permission notice
- appear in all copies, and that the name of Bellcore not be
- used in advertising or publicity pertaining to this
- material without the specific, prior written permission
- of an authorized representative of Bellcore. BELLCORE
- MAKES NO REPRESENTATIONS ABOUT THE ACCURACY OR SUITABILITY
- OF THIS MATERIAL FOR ANY PURPOSE. IT IS PROVIDED "AS IS",
- WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES.
- */
- #define MMCODE
- #include <stdio.h>
- #include <ctype.h>
- #define NEWLINE_CHAR 10
- char mmencode_c[] =
- "$Id: mmencode.c,v 1.1 2000/01/15 01:45:32 edwardc Exp $";
- extern char *index();
- static char basis_64[] =
- "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
- static char index_64[128] = {
- -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
- -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
- -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,
- 52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1,-1,-1,-1,
- -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11,12,13,14,
- 15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1,
- -1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
- 41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1
- };
- #define char64(c) (((c) < 0 || (c) > 127) ? -1 : index_64[(c)])
- /* the following gets a character, but fakes it properly into two chars if there's a newline character */
- static int InNewline=0;
- int nextcharin(infile, PortableNewlines)
- FILE *infile;
- int PortableNewlines;
- {
- int c;
- if (!PortableNewlines) return(getc(infile));
- if (InNewline) {
- InNewline = 0;
- return(10); /* LF */
- }
- c = getc(infile);
- if (c == NEWLINE_CHAR) {
- InNewline = 1;
- return(13); /* CR */
- }
- return(c);
- }
- to64(infile, outfile, PortableNewlines)
- FILE *infile, *outfile;
- int PortableNewlines;
- {
- int c1, c2, c3, ct=0;
- InNewline = 0; /* always reset it */
- while ((c1 = nextcharin(infile, PortableNewlines)) != EOF) {
- c2 = nextcharin(infile, PortableNewlines);
- if (c2 == EOF) {
- output64chunk(c1, 0, 0, 2, outfile);
- } else {
- c3 = nextcharin(infile, PortableNewlines);
- if (c3 == EOF) {
- output64chunk(c1, c2, 0, 1, outfile);
- } else {
- output64chunk(c1, c2, c3, 0, outfile);
- }
- }
- ct += 4;
- if (ct > 71) {
- putc('n', outfile);
- ct = 0;
- }
- }
- if (ct) putc('n', outfile);
- fflush(outfile);
- }
- output64chunk(c1, c2, c3, pads, outfile)
- FILE *outfile;
- {
- putc(basis_64[c1>>2], outfile);
- putc(basis_64[((c1 & 0x3)<< 4) | ((c2 & 0xF0) >> 4)], outfile);
- if (pads == 2) {
- putc('=', outfile);
- putc('=', outfile);
- } else if (pads) {
- putc(basis_64[((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6)], outfile);
- putc('=', outfile);
- } else {
- putc(basis_64[((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6)], outfile);
- putc(basis_64[c3 & 0x3F], outfile);
- }
- }
- PendingBoundary(s, Boundaries, BoundaryCt)
- char *s;
- char **Boundaries;
- int *BoundaryCt;
- {
- int i;
- for (i=0; i < *BoundaryCt; ++i) {
- if (!strncmp(s, Boundaries[i], strlen(Boundaries[i]))) {
- char Buf[2000];
- strcpy(Buf, Boundaries[i]);
- strcat(Buf, "--n");
- if (!strcmp(Buf, s)) *BoundaryCt = i;
- return(1);
- }
- }
- return(0);
- }
- /* If we're in portable newline mode, we have to convert CRLF to the
- local newline convention on output */
- static int CRpending = 0;
- almostputc(c, outfile, PortableNewlines)
- int c;
- FILE *outfile;
- int PortableNewlines;
- {
- if (CRpending) {
- if (c == 10) {
- putc(NEWLINE_CHAR, outfile);
- } else {
- putc(13, outfile);
- putc(c, outfile);
- }
- CRpending = 0;
- } else {
- if (PortableNewlines && c == 13) {
- CRpending = 1;
- } else {
- putc(c, outfile);
- }
- }
- }
- from64(infile, outfile, boundaries, boundaryct, PortableNewlines)
- FILE *infile, *outfile;
- char **boundaries;
- int *boundaryct;
- int PortableNewlines;
- {
- int c1, c2, c3, c4;
- int newline = 1, DataDone = 0;
- /* always reinitialize */
- CRpending = 0;
- while ((c1 = getc(infile)) != EOF) {
- if (isspace(c1)) {
- if (c1 == 'n') {
- newline = 1;
- } else {
- newline = 0;
- }
- continue;
- }
- if (newline && boundaries && c1 == '-') {
- char Buf[200];
- /* a dash is NOT base 64, so all bets are off if NOT a boundary */
- ungetc(c1, infile);
- fgets(Buf, sizeof(Buf), infile);
- if (boundaries
- && (Buf[0] == '-')
- && (Buf[1] == '-')
- && PendingBoundary(Buf, boundaries, boundaryct)) {
- return;
- }
- fprintf(stderr, "Ignoring unrecognized boundary line: %sn", Buf);
- continue;
- }
- if (DataDone) continue;
- newline = 0;
- do {
- c2 = getc(infile);
- } while (c2 != EOF && isspace(c2));
- do {
- c3 = getc(infile);
- } while (c3 != EOF && isspace(c3));
- do {
- c4 = getc(infile);
- } while (c4 != EOF && isspace(c4));
- if (c2 == EOF || c3 == EOF || c4 == EOF) {
- fprintf(stderr, "Premature EOF!n");
- return;
- }
- if (c1 == '=' || c2 == '=') {
- DataDone=1;
- continue;
- }
- c1 = char64(c1);
- c2 = char64(c2);
- almostputc(((c1<<2) | ((c2&0x30)>>4)), outfile, PortableNewlines);
- if (c3 == '=') {
- DataDone = 1;
- } else {
- c3 = char64(c3);
- almostputc((((c2&0XF) << 4) | ((c3&0x3C) >> 2)), outfile, PortableNewlines);
- if (c4 == '=') {
- DataDone = 1;
- } else {
- c4 = char64(c4);
- almostputc((((c3&0x03) <<6) | c4), outfile, PortableNewlines);
- }
- }
- }
- if (CRpending) putc(13, stdout);
- }
- #define hexchar(c) (((c) < 0 || (c) > 127) ? -1 : index_hex[(c)])
- int
- mm(int encode, char *fin, char *fout)
- {
- int portablenewlines = 0;
- FILE *in, *out;
-
- if ( fin != NULL )
- in = fopen(fin, "r");
- else
- in = stdin;
-
- if ( fout != NULL )
- out = fopen(fout, "w");
- else
- out = stdout;
-
- if (encode)
- to64(in, out, portablenewlines);
- else
- from64(in, out, NULL, 0, portablenewlines);
-
- if ( fout != NULL )
- fclose(out);
-
- if ( fin != NULL )
- fclose(in);
-
- return(0);
- }