Thread: argc

#include <stdlib.h>

int charCount = _atoi(argv[0]);

.......maybe

Umm, wouldn't you want argv[1]? Isn't argv[0] the name that invoked the program?

hell, i dunno....i've never used argc and argv before

Perhaps if you wish to be safe, you'd do:

Code:

if( argc > 0 )
{
    cCount = atoi( argv[ argc - 1 ] );
}
else
{
    cCount = some_default_value;
}

There's a section in the FAQ about using command line arguments if you wish to read it. It's also there even if you don't wish to read it.

Quzah.

Originally Posted by Calavera

Argv[1] will be the program
Argv[2] will be the number of tests

Ex: character(name of the program) 5(Number of times of the test)

No it won't. If it happens to be there at all, the name of the program will reside in argv[0] and the first of the user supplied arguments will begin on argv[1]. If it doesn't, then the user supplied arguments will begin on argv[0].

I suggest YOU read the FAQ entry.

Quzah.

hmm... I'm not sure about C, but for C++ the standard reads "argv[0] shall be the pointer to the initial character of a NTMBS (nul terminated multi-byte string) that represents the name used to invoke the program or "".".

C: A Reference Manual, 5th Edition
Page 303:

When arguments are declared, those arguments are set up by the execution enviorn-
ment and are not directly under control of the C programmer. The parameter argc is the
count of the number of "program arguments" or "options" supplied to the program when it
was invoked by a user or another program. The parameter argv is a vector of pointers to
strings representing the program arguments. The first string, argv[0], is the name of the
program; if the name is not available, argv[0][0] must be '\0'. The string argv[i],
for i=1, ..., argc-1, is the ith program argument. Standard C requires that argv[argc]]
be a null pointer, but it is not so in some older implementations. The vector argv and the
strings to which it points must be modifiable, and their values must not be changed by the
implementation or host system during program execution. If the implementation does not
support mixed-case strings, then the strings stored in argv must be in lower case.

Quzah.

hmm... doesnt that imply that argv[1] will always point to the first user supplied argument?

Yeah. Looks like I misstated. I was thinking when I wrote it, that you could have user arguments without having the name of the program there, because I knew that you could have an instance where there was no program name in argc[0]. I'll blame it on the beer.

Personally I've never seen an instance where there is no program name specified, which is why I was assuming that arguments would simply take the place of it. (Then I looked up the reference for my last post.)

Quzah.