create array of pointers to files

c file io argv
Hristo picture Hristo · Feb 11, 2010 · Viewed 21.7k times · Source

How would I go about making an array of file pointers in C?
I would like to create an array of file pointers to the arguments of main... like a1.txt, a2.txt, etc... So I would run ./prog arg1.txt arg2.txt arg3.txtto have the program use these files.
Then the argument for main is char **argv

From argv, I would like to create the array of files/file pointers. This is what I have so far.

FILE *inputFiles[argc - 1];
int i;
for (i = 1; i < argc; i++)
    inputFiles[i] = fopen(argv[i], "r");

Answer

kennytm picture kennytm · Feb 11, 2010

The code is fine, but remember to compile in C99.

If you don't use C99, you need to create the array on heap, like:

FILE** inputFiles = malloc(sizeof(FILE*) * (argc-1));

// operations...

free(inputFiles);

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