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/* public domain */
/* BASE64 on stdin -> converted data on stdout */
#include <stdio.h>
#ifdef _WIN32
#ifndef WIN32
#define WIN32
#endif
#endif
#ifdef WIN32
#include <io.h>
#include <fcntl.h>
#endif
unsigned char alphabet[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
int
main()
{
static char inalphabet[256], decoder[256];
int i, bits, c, char_count, errors = 0;
#ifdef WIN32
_setmode( _fileno(stdout), _O_BINARY);
#endif
for (i = (sizeof alphabet) - 1; i >= 0 ; i--) {
inalphabet[alphabet[i]] = 1;
decoder[alphabet[i]] = i;
}
char_count = 0;
bits = 0;
while ((c = getchar()) != EOF) {
if (c == '=')
break;
if (c > 255 || ! inalphabet[c])
continue;
bits += decoder[c];
char_count++;
if (char_count == 4) {
putchar((bits >> 16));
putchar(((bits >> 8) & 0xff));
putchar((bits & 0xff));
bits = 0;
char_count = 0;
} else {
bits <<= 6;
}
}
if (c == EOF) {
if (char_count) {
fprintf(stderr, "base64-decode: base64 encoding incomplete: at least %d bits truncated",
((4 - char_count) * 6));
errors++;
}
} else { /* c == '=' */
switch (char_count) {
case 1:
fprintf(stderr, "base64-decode: base64 encoding incomplete: at least 2 bits missing");
errors++;
break;
case 2:
putchar((bits >> 10));
break;
case 3:
putchar((bits >> 16));
putchar(((bits >> 8) & 0xff));
break;
}
}
exit(errors ? 1 : 0);
}
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