This may be a bad question but I would like to know what the -o called when you have something like
g++ -o hello.out hello.cpp
and how I can implement them in a C++ program
Asked
Active
Viewed 80 times
-3
beenjaminnn
- 752
- 1
- 11
- 23
-
I think you are messing things here.... – Netwave Jan 25 '14 at 19:13
-
1It's called options or switches. As for how to implement it, just parse arguments from main... – Filipe Gonçalves Jan 25 '14 at 19:14
-
1Check out [GCC Command Options](http://gcc.gnu.org/onlinedocs/gcc-3.0/gcc_3.html). – herohuyongtao Jan 25 '14 at 19:14
-
Sorry that it was a bad question, but I have never heard them referred to by name – beenjaminnn Jan 25 '14 at 19:16
2 Answers
3
These are command line arguments.
A command-line argument or parameter is an item of information provided to a program when it is started. A program can have many command-line arguments that identify sources or destinations of information, or that alter the operation of the program.
The -x, --x or /x forms are generally considered options or switches.
The program run determines what is actually done; in C/C++ the arguments are directly accessible in the argv parameter to the main function. There are are also libraries to make parsing easier.
Community
- 1
- 1
user2864740
- 60,010
- 15
- 145
- 220
2
-o is an option passed to the compiler g++. It let give the name of the file to produce. Here it means "compile file hello.cpp to produce a file called hello.out".
You can read the manual to find out more: man g++
If you want to know how to use flags like this in your program, you may eg. refer to Arguments to main in C
In short: if you define your main function by int main(int argc, char **argv);, then a potential -o flag provided by the user, could be read from argv
