C String Comparison

[kidko]

I'm trying to write a function that reads keystrokes using the NCURSES library's "getstr(str )" function (where "str" is a C-style string, and it modifies the value of it directly). However, my code does not ever cause the program to exit, and even when typing exactly the word "quit," no backspace or anything, it gives me the "Unknown command" message. I'm writing in C++ using the G++ compiler on Kubuntu Linux 7.04.
[code=cpp]display::clear_ messages(); // Clear the top line of the screen
echo(); // Show the characters being typed
cbreak(); // Wait for <enter>
char text[20];
getstr(text); // changes text[20] directly
noecho(); // Don't show characters
raw(); // Give me the keystrokes directly
if (text == "quit") {
exit(0);
} else {
display::messag e(display::blan k_line);
move(0,0); // Move to top line
printw("Unknown command '%s'",text); // works like printf()
}[/code]

Thanks in advance!

[oler1s]

text == "quit"

Will always return false.

C strings are not first class citizens. Unlike say two ints, you cannot compare two C strings and have that translated to comparing the values of the strings. Referring to a string is the same as referring to an array of type char, which translates to you referring to a char pointer. Do you follow?

Hence, == compares char pointers. Not what you are looking for. You probably want to use strcpy (or better yet, strncpy).

[keerthiramanarayan]

[code=cpp]
if (text == "quit") {
[/code]

should be replaced by
[code=cpp]
if(strncmp(text ,"quit",4) == 0){
[/code]

[weaknessforcats]

If you stop using the C string library and start using the C++ string object you will have fewer problems.

[kidko]

C strings are not first class citizens. Unlike say two ints, you cannot compare two C strings and have that translated to comparing the values of the strings. Referring to a string is the same as referring to an array of type char, which translates to you referring to a char pointer. Do you follow?

Hence, == compares char pointers. Not what you are looking for. You probably want to use strcpy (or better yet, strncpy).

So it was comparing memory addresses? Definitely not what I'm looking for. But why use str(n)cpy? Doesn't that copy the string (or n letters of it), while what I want is a comparison?

should be replaced by
[code=cpp]
if(strncmp(text ,"quit",4) == 0){
[/code]

Aha. Exactly what I needed.

Thanks, everybody, for the feedback/help.