cosmopolitan/tool/decode/unhex.c
2024-08-04 12:52:25 -07:00

30 lines
1.2 KiB
C

/*─────────────────────────────────────────────────────────────────╗
│ To the extent possible under law, Justine Tunney has waived │
│ all copyright and related or neighboring rights to this file, │
│ as it is written in the following disclaimers: │
│ • http://unlicense.org/ │
│ • http://creativecommons.org/publicdomain/zero/1.0/ │
╚─────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/str/tab.h"
/**
* @fileoverview Hex to binary converter program.
* Non-hex bytes are ignored. If you've got imposter syndrome you could
* call this a compiler and start coding in hex.
*/
int main() {
int h, o, t = -1;
while ((o = getchar()) != -1) {
if ((h = kHexToInt[o & 255]) != -1) {
if (t != -1) {
putchar(t * 16 + h);
h = -1;
}
t = h;
}
}
}