argv[0] in my c++ program shows :/Users/myname/Library/Developer/Xcode/DerivedData/project4/Build/Products/Debug/project4
Instead of the first argument I enter to it. Can I change this?
Asked
Active
Viewed 667 times
-3
Caleb Kleveter
- 11,170
- 8
- 62
- 92
Fatwhale
- 11
-
3This is correct and by definition. There is no way to change it. – MrTux Nov 14 '15 at 22:16
-
1Which is correct. That's it. – Zehryo Karham Nov 14 '15 at 22:16
-
If you want the first supplied argument use `argv[1]` – TheQAGuy Nov 14 '15 at 22:17
-
You should read this: http://stackoverflow.com/questions/383973/is-args0-guaranteed-to-be-the-path-of-execution – NathanOliver Nov 14 '15 at 22:22
2 Answers
2
The C programming system RELIES on argv[0] containing the name of the program itself (with or without path, depending on the system you use). Many programs depend on that to find the path where the program lives, for example.
Your first argument will be in argv[1], and the last one at argv[argc-1].
In other words:
/usr/bin/myprog foo bar baz
will have
argc = 4
argv[0] = /usr/bin/myprog
argv[1] = foo
argv[2] = bar
argv[3] = baz
If this wasn't followed, all standard programs would go wrong.
Mats Petersson
- 126,704
- 14
- 140
- 227
0
Yes, you can :-) Use this:
argv[0] = argv[1];
And you will get first argument in argv[0].
But don't do this in real programs, please.
vladon
- 8,158
- 2
- 47
- 91
-
You would have to do `for(i = argc - 1; i >= 1; i--) argv[i-1] = argv[i];` tho', if there is more than 1 argument. – Mats Petersson Nov 14 '15 at 22:29
-
@MatsPetersson Formally, no. OP wants only that first argument will be in `argv[0]`, and nothing more ;-). – vladon Nov 14 '15 at 22:31
-