#include "shared.h"

#include <errno.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

void error(const char* format, ...) {
    va_list list;
    va_start(list, format);

    vfprintf(stderr, format, list);
    fprintf(stderr, "\n");
    exit(EXIT_FAILURE);
}

FILE* get_file(const char* path, const char* type) {
    FILE* file = fopen(path, type);
    if (file == NULL) {
        error("error: failed to open file %s: %s", path, strerror(errno));
    }
    return file;
}

long int get_number(const char* text) {
    char* end;
    long int n = strtol(text, &end, 10);
    if (text == end) {
        error("error: %s is not a valid number", text);
    }
    return n;
}

bool streql(const char* a, const char* b) {
    if (*a != *b) return false;
    int n = 0;
    while (true) {
        if (*(a+n) != *(b+n)) return false;
        if (*(a+n) == '\0') return true;
        ++n;
    }
}

bool prefix(const char* pre, const char* str) {
    return strncmp(pre, str, strlen(pre)) == 0;
}