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kernels: import bf from movfuscator

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Zihao Yu 2023-07-01 01:12:31 +08:00
parent 6b5c2ad2d3
commit b122a7fa12
1 changed files with 84 additions and 0 deletions
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kernels/bf/bf.c Normal file
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/* from http://rosettacode.org/wiki/Execute_Brain****#C */
/* This is the Neutron brainfuck interpreter.
* It's rather small and dense, but still readable, more or less.
*
* Robert de Bath -- 2013.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct bfi { char cmd; struct bfi *next, *jmp; };
struct mem { char val; struct mem *next, *prev; };
int main(int argc, char **argv)
{
FILE * ifd;
int ch;
struct bfi *p=0, *n=0, *j=0, *pgm = 0;
struct mem *m = calloc(1,sizeof*m);
setbuf(stdout, NULL);
/* Open the file from the command line or stdin */
if (argc < 2 || strcmp(argv[1], "-") == 0) ifd = stdin;
else if ((ifd = fopen(argv[1], "r")) == 0) { perror(argv[1]); exit(1); }
/*
* For each character, if it's a valid BF command add it onto the
* end of the program. If the input is stdin use the '!' character
* to mark the end of the program and the start of the data, but
* only if we have a complete program. The 'j' variable points
* at the list of currently open '[' commands, one is matched off
* by each ']'. A ']' without a matching '[' is not a legal BF
* command and so is ignored. If there are any '[' commands left
* over at the end they are not valid BF commands and so are ignored.
*/
while((ch = getc(ifd)) != EOF && (ifd!=stdin || ch != '!' || j || !pgm)) {
if (ch == '<' || ch == '>' || ch == '+' || ch == '-' ||
ch == ',' || ch == '.' || ch == '[' || (ch == ']' && j)) {
if ((n = calloc(1, sizeof*n)) == 0) {
perror(argv[0]); exit(1);
}
if (p) p->next = n; else pgm = n;
n->cmd = ch; p = n;
if (n->cmd == '[') { n->jmp=j; j = n; }
else if (n->cmd == ']') {
n->jmp = j; j = j->jmp; n->jmp->jmp = n;
}
}
}
/* Ignore any left over '[' commands */
while(j) { p = j; j = j->jmp; p->jmp = 0; p->cmd = ' '; }
if (ifd!=stdin) fclose(ifd);
/* Execute the loaded BF program */
for(n=pgm; n; n=n->next)
switch(n->cmd)
{
case '+': m->val++; break;
case '-': m->val--; break;
case '.': putchar(m->val); break;
case ',': if((ch=getchar())!=EOF) m->val=ch; break;
case '[': if (m->val == 0) n=n->jmp; break;
case ']': if (m->val != 0) n=n->jmp; break;
case '<':
if (!(m=m->prev)) {
fprintf(stderr, "%s: Hit start of tape\n", argv[0]);
exit(1);
}
break;
case '>':
if (m->next == 0) {
if ((m->next = calloc(1,sizeof*m)) == 0) {
perror(argv[0]); exit(1);
}
m->next->prev = m;
}
m=m->next;
break;
}
return 0;
}