strtok - Why File is not deleting in C Language

Question

Hello I am new in c and ? have homework about tcp program and one poin in this project I cant pass can anywone help me please

StartsWithDEL() this function catch DEL user.txt like return true trim() like trim and give only file name user.txt

BUT when I write client line DEL user.txt is not going delete

      if (StartsWithDEL(line,"DEL") == 1)
            {
                 char *deltoken = strtok(line, "DEL");
                 char *itemDeleting = trim(deltoken);
//in this section I cach file name but cant delete it 
                    remove(itemDeleting);
                    send(client, "
" ,strlen("
"),0);
    
             }

question from:https://stackoverflow.com/questions/65648026/why-file-is-not-deleting-in-c-language

Answer 1

Your call to strtok() in incorrect. The second argument is a string or allowed token delimiters, which in your case a . If you call it with "DEL", it will overwrite the D with and deltoken will point to that empty string.

If you choose to use strtok() then:

char* token = strtok( line, " " ) ;

if( strcmp( token, "DEL" ) == 0 )
{
    char* itemDeleting = strtok( NULL, " " ) ;
    remove(itemDeleting);
    send(client, "
" ,strlen("
"),0);
}

However if is simpler to avoid the complexity of strtok(), and the fact that it modifies line by inserting nuls makes it undesirable in many cases. The code above also won't work if a filename may contains spaces.

There are many alternative solutions, for example:

size_t delimiter_index = strcspn( line, " " ) ;

if( strncmp( line, "DEL", delimiter_index ) == 0 )
{
    char* itemDeleting = &line[delimiter_index] ;
    while( *itemDeleting == 0 && *itemDeleting != '' ) itemDeleting++ ;

    remove(itemDeleting);
    send(client, "
" ,strlen("
"),0);
}

Since I have no idea what StartsWithDEL() or trim() so I have avoided them.