CODEWITHSUNDEEP
cargv
baobobs
baobobs

Reputation: 703

Pass argv to function to populate global variable

I'm trying to populate a global int variable by passing command line arguments to a function. When I do this, I get warnings (see below), as well as a funky return number (such as 52 instead of the expected 49).

Any hints would be greatly appreciated. This is HW - but only a very small portion of the overall assignment.

#include <stdio.h> 
#include <stdlib.h>
#include "kangarooHeaders.h"


int             numJoeys                = MIN_NUM_LEGAL_JOEYS - 1;

int main (int argc, char* argv[])
{
        initializeNumJoeys(argc,argv);
        printf("%d", numJoeys);
}

void initializeNumJoeys(void argc, void *argv[])
{
        char line[LINE_LEN];
        if (argc > MAMAS_NUM_JOEYS_CMD_LINE_INDEX)
                numJoeys = *argv[1];
}

argv_test.c:13: warning: conflicting types for ‘initializeNumJoeys’
argv_test.c:9: warning: previous implicit declaration of ‘initializeNumJoeys’ was here

Upvotes: 0

Views: 1137

Answers (1)

Iharob Al Asimi
Iharob Al Asimi

Reputation: 53046

Put this above the main() function

void initializeNumJoeys(int argc, char *argv[]);

the reason is implicit function declaration, the compiler doesn't find a prototype for initializeNumJoeys() and implicitly declares it as

int initializeNumJoeys();

so when it finds the definition, then it's conflicting with the previous declaration.

Also, change this

numJoeys = *argv[1];

to

numJoeys = strtol(argv[1], NULL, 10);

and also, the function signature is wrong

void initializeNumJoeys(void argc, void *argv[])
             /*           ^ should be int */

so change it to

void initializeNumJoeys(int argc, void *argv[])

don't forget to fix the prototype.

Upvotes: 3

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