read_text_file - quickly reads a text file from disk

read_text_file.c

char* read_text_file(const char* const filenm){
    char* buf;
    long unsigned int len;
    FILE* const f=fopen(filenm, "r");
    if(f){
        fseek(f, 0, SEEK_END);
        len=ftell(f);
        fseek(f, 0, SEEK_SET);
        buf=(char*)malloc(len+1);
        if(buf)
            fread(buf, 1, len, f);
        buf[len]=0;
        fclose(f);
    }else buf=0;
    return buf;
}