repairs path that's broken by windows update duh

env_repair.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int needed_vars(int size) {
	int vars_needed = size/2000;
	if (vars_needed * 2000 < size) {
		vars_needed++;
	}
	return vars_needed;
}

int consume(char **arr, int sarr, char *out, int length) {
	int i = 0;
	while (length > 0 && i < sarr && strlen(arr[i]) <= length) {
		strcat(out, arr[i]);
		length -= strlen(arr[i]);
		i++;
	}
	return i;
}

int main(int argc, char* argv[]) {
	if (argc != 2) {
		printf("Usage: %s in", argv[0]);
		return 1;
	}

	char **arr = malloc(sizeof(char*)*1);
	int ix = 0;
	int size = 0;
	FILE* f = fopen(argv[1], "r");
	char buf[256];

	while (NULL != fgets(buf, 256, f)) {
		int l = strlen(buf);
		if (l > 0 && buf[0] != '#') {
			size += 1+l;
			arr[ix] = malloc(sizeof(char)*l);
			if (buf[l-1] == '\n') {
				buf[l-1] = ';';
			} else {
				buf[l] = ';';
				buf[l+1] = '\0';
			}
			strcpy(arr[ix], buf);
			ix++;
		}
	}

	fclose(f);

	int vars_needed = needed_vars(size);
	size += vars_needed * 10; // %pathXXX%;
	int vars_needed2 = needed_vars(size);
	while (vars_needed < vars_needed2) {
		vars_needed = vars_needed2;
		size += 10 * (vars_needed2-vars_needed);
		vars_needed2 = needed_vars(size);
	}

	vars_needed2 = vars_needed;

	int padding = (vars_needed-1) * 10;

	fprintf(stderr, "Vars: %d. Takes %d characters.\n", vars_needed, padding);
	
	char out[2048] = {0};
	int length = 2000-padding;
	int jx = 0;
	while (length > 0 && jx < ix && strlen(arr[jx]) <= length) {
		strcat(out, arr[jx]);
		length -= strlen(arr[jx]);
		jx++;
	}
	while (vars_needed2 > 1) {
		vars_needed2--;
		char s[11];
		sprintf(s, "%%path%d%%;", vars_needed2);
		strcat(out, s);
	}
	printf("%s\n\n", out);
	ix -= jx;

	while (vars_needed > 1) {
		vars_needed--;
		printf("%%path%d%%\n", vars_needed);
		int count = consume(arr, ix, out, 2000);
		fprintf(stderr, "To go: %d\n", ix-count);
		ix -= count;
		arr += count;
		printf("%s\n\n", out);
	}
	
	return 0;
}