How can I delete the contents of a file in c, what function should I use?
#include <stdio.h>
#include <stdlib.h>
void main(){
char hello[13] = "Hello World!";
char path[12] = "arquivo.txt";
FILE* arquivo;
arquivo = fopen(path, "a+");
fprintf(arquivo, hello);
printf("%s foi adicionado ao arquivo %s", hello, path);
/*
arquivo = fopen(path, "w");
fclose(arquivo);
*/
}
To delete the contents of a file in C just open with w mode:
fopen(caminho_para_o_arquivo, "w");
Now in your case it happens that you already opened it previously with a+ :
void main(){
...
arquivo = fopen(path, "a+");
...
arquivo = fopen(path, "w");
fclose(arquivo);
}
So the second try opening does not delete the content. To fix, put a fclose before opening again:
arquivo = fopen(path, "a+");
fclose(arquivo);
...
arquivo = fopen(path, "w");
fclose(arquivo);
Or even open to add content with a+ since it will then delete! Simplify and leave only:
fclose(fopen(path, "w"));