can't open file - No file or directory

[sdsjohnny]

I have a weird issue. Can some one help.

When I hardcode abc.bin to inputFileName - I can open the file in cpp. But when I pass the same using an optional argument, it fails. Note that in both cases, fprintf, prints the inputFileName as abc.bin properly.

I get can't open - no file or directory.

   main()
   {
   char * inputFileName;
   char * optarg;
   inputFileName = optarg;  //doesn't work.
   //inputFileName = "abc.bin"; //Works
    fprintf(stderr, "inputFileName:%s \n",inputFileName);
   }

Another function:
    FILE *inFile;
    if ( inFile != NULL )
    {
        inFile = fopen(inputFileName, "r+b");
        if ( inFile == NULL )
        {
            fprintf(stderr, 
                    "%s: can't open file %s: %s\n",
                    ProgName, inputFileName, strerror(errno));
            return NULL;
        }
    }

Thank you

[gerard4143]

Does

char * optarg;

point to valid memory? Its not clear in your posting.

[sdsjohnny]

Sorry.

extern char * optarg; declared in xyz.h file.
#include "xyz.h"
main(int argc, **argv)
{
char * inputFileName;

c = getopt_long_only(argc, argv, "aBc:Cd:e:E::GH::iIlL:m:Op:P:r:t:T:uUv::VZ",
long_options, &option_index); //some open source that gets optargs given argv

inputFileName = optarg; //doesn't work.
//inputFileName = "abc.bin"; //Works
fprintf(stderr, "inputFileName:%s \n",inputFileName); //It prints as abc.bin in both cases. That is weird, but does not work for inputFileName=optarg!!
}

Another function:
FILE *inFile;
if ( inFile != NULL )
{
inFile = fopen(inputFileName, "r+b");
if ( inFile == NULL )
{
fprintf(stderr,
"%s: can't open file %s: %s\n",
ProgName, inputFileName, strerror(errno));
return NULL;
}
}