collapseos/tools/ttysafe.c

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2020-01-11 22:45:22 -05:00
#include <stdlib.h>
#include <stdio.h>
/* Converts stdin to a content that is "tty safe", that is, that it doesn't
* contain ASCII control characters that can mess up serial communication.
* How it works is that it leaves any char > 0x20 intact, but any char <= 0x20
* is replaced by two chars: char|0x80, 0x20. A 0x20 char always indicate "take
* the char you've just received and unset the 7th bit from it".
*/
int main(void)
{
int c = getchar();
while (c != EOF) {
if (c <= 0x20) {
putchar(c|0x80);
putchar(0x20);
} else {
putchar(c&0xff);
}
c = getchar();
}
return 0;
}