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/*
* i25.c -- "interleaved 2 of 5"
*
* Copyright (c) 1999,2000 Alessandro Rubini (rubini@gnu.org)
* Copyright (c) 1999 Prosa Srl. (prosa@prosa.it)
* Copyright (c) 2010, 2011 Giuseppe Scrivano (gscrivano@gnu.org)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "barcode.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
static char *codes[] = {
"11331", "31113", "13113", "33111", "11313",
"31311", "13311", "11133", "31131", "13131"
};
static char *guard[] = {"a1a1", "c1a"}; /* begin end */
int Barcode_i25_verify(unsigned char *text)
{
if (!text[0])
return -1;
while (*text && isdigit(*text))
text++;
if (*text)
return -1; /* a non-digit char */
return 0; /* ok */
}
int Barcode_i25_encode(struct Barcode_Item *bc)
{
char *text;
char *partial; /* dynamic */
char *textinfo; /* dynamic */
char *textptr, *p1, *p2, *pd;
int i, len, sum[2], textpos, usesum = 0;
if (bc->partial)
free(bc->partial);
if (bc->textinfo)
free(bc->textinfo);
bc->partial = bc->textinfo = NULL; /* safe */
if (!bc->encoding)
bc->encoding = strdup("interleaved 2 of 5");
text = bc->ascii;
if (!bc->ascii) {
bc->error = EINVAL;
return -1;
}
if ((bc->flags & BARCODE_NO_CHECKSUM)) usesum = 0; else usesum = 1;
/* create the real text string, padded to an even number of digits */
text = malloc(strlen(bc->ascii) + 3); /* leading 0, checksum, term. */
if (!text) {
bc->error = errno;
return -1;
}
/* add the leading 0 if needed */
i = strlen(bc->ascii) + usesum;
if (i % 2) {
/* add a leading 0 */
text[0] = '0';
strcpy(text+1, bc->ascii);
} else {
strcpy(text, bc->ascii);
}
/* add the trailing checksum if needed, the leading 0 is ignored */
if (usesum) {
sum[0] = sum[1] = 0;
for (i=0; text[i]; i++)
sum[i%2] += text[i]-'0';
/*
* The "even" sum must be multiplied by three, and the *
* rightmost digit is defined as "even". The digits' position
* is already correct, whether or not we added a leading zero.
* (e.g., they are in pos. 0..4 or 1..4 of the string)
*/
i = sum[0] * 3 + sum[1];
strcat(text, "0");
text[strlen(text)-1] += (10 - (i%10)) % 10;
}
/* the partial code is 5 * (text + check) + 4(head) + 3(tail) + term. */
partial = malloc( (strlen(text) + 3) * 5 +2); /* be large... */
if (!partial) {
bc->error = errno;
free(text);
return -1;
}
/* the text information is at most "nnn:fff:c " * (strlen+1) +term */
textinfo = malloc(10*(strlen(text)+1) + 2);
if (!textinfo) {
bc->error = errno;
free(partial);
free(text);
return -1;
}
strcpy(partial, "0"); /* the first space */
strcat(partial, guard[0]); /* start */
textpos = 4; /* width of initial guard */
textptr = textinfo;
len = strlen(text);
for (i=0; i<len; i+=2) {
if (!isdigit(text[i]) || !isdigit(text[i+1])) {
bc->error = EINVAL; /* impossible if text is verified */
free(partial);
free(textinfo);
free(text);
return -1;
}
/* interleave two digits */
p1 = codes[text[i]-'0'];
p2 = codes[text[i+1]-'0'];
pd = partial + strlen(partial); /* destination */
while (*p1) {
*(pd++) = *(p1++);
*(pd++) = *(p2++);
}
*pd = '\0';
/* and print the ascii text (but don't print the checksum, if any */
if (usesum && strlen(text+i)==2) {
/* print only one digit, discard the checksum */
sprintf(textptr, "%i:12:%c ", textpos, text[i]);
} else {
sprintf(textptr, "%i:12:%c %i:12:%c ", textpos, text[i],
textpos+9, text[i+1]);
}
textpos += 18; /* width of two codes */
textptr += strlen(textptr);
}
textptr[-1] = '\0'; /* overwrite last space */
strcat(partial, guard[1]);
bc->partial = partial;
bc->textinfo = textinfo;
free(text);
return 0;
}
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