bfc.c

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

int CheckFront(int, char *);
int CheckBack(int, char *);

int main(int argc, char *argv[]){
	char example[] = {"例:bfc ソースファイル [出力ファイル名]"};
	char sourceName[32];
	char outName[32] = {"out.txt"};
	char sourceCode[1000] = {""};
	char outPut[1000] = {""};
	char buf;
	FILE *sfp, *ofp;	
	int count;
	int pc = 0, mp = 0;
	int memory[100] = {0};

	if(argc > 3){
		fprintf(stderr, "引数が多すぎます %s\n", example);
		return 0;
	}
	if(argc == 1){
		fprintf(stderr, "引数がありません %s\n", example);
		return 0;
	}
	if(strlen(argv[1]) > 31){
		fprintf(stderr, "引数が大きすぎます。31文字以内で入力してください。\n");
		return 0;
	}

	strcpy(sourceName, argv[1]);
	if(argc == 3)
		strcpy(outName, argv[2]);
	
	sfp = fopen(sourceName, "r");
	ofp = fopen(outName, "w");

	count = 0;
	while(count < 999){
		if(fscanf(sfp, "%c", &buf) == EOF)	break;
		if(buf != '\n'){
			sourceCode[count] = buf;
			count++;
		}
	}
	sourceCode[count] = '\0';
	fclose(sfp);
	
	count = 0;
	while(sourceCode[pc] != '\0'){
		switch(sourceCode[pc]){
			case '>':
				mp++;
				break;
			case '<':
				mp--;
				break;
			case '+':
				memory[mp]++;
				break;
			case '-':
				memory[mp]--;
				break;
			case '.':
				outPut[count] = memory[mp];
				count++;
				break;
			case ',':
				scanf("%c", &buf);
				memory[mp] = buf;
				break;
			case '[':
				if(memory[mp] == 0){
					pc = CheckFront(pc, sourceCode);
					if(pc >= strlen(sourceCode))
						return 0;
				}
				break;
			case ']':
				if(memory[mp] != 0){
					pc = CheckBack(pc, sourceCode);
					if(pc < 0)
						return 0;
				}
				break;
			default:
				break;
		}
		if(mp > 99){
			fprintf(stderr, "memory error\n");
			return 0;
		}
		pc++;
	}

	outPut[count] = '\0';
	fprintf(ofp, "%s", outPut);
	fclose(ofp);
	return 0;
}

int CheckFront(int pc, char sourceCode[1000]){
	int length = strlen(sourceCode);
	int count = 0;
	pc++;
	while(1){
		if(sourceCode[pc] == '[')
			count++;
		if(sourceCode[pc] == ']'){
			if(count == 0)
				return pc + 1;
			else
				count--;
		}
	pc++;
	if(pc >= length)
		break;
	}
	fprintf(stderr, "']'がありません\n");
	return -1;
}

int CheckBack(int pc, char sourceCode[1000]){
	int length = strlen(sourceCode);
	int count = 0;
	pc--;
	while(1){
		if(sourceCode[pc] == ']')
			count++;
		if(sourceCode[pc] == '['){
			if(count == 0)
				return pc;
			else
				count--;
		}
	pc--;
	if(pc < 0)
		break;
	}
	fprintf(stderr, "'['がありません\n");
	return -1;
}