using fork/execvp to catenate a file

Hi guys,
I'm still working on my shell. I'm trying to implement a function typefile that will take a command line input as follows:

> type <file1>

This command will implement a catenation of file1, equal to the command cat <file1>

I need to use execvp() and fork() system calls to create a new process that will type/cat any text file. In my code below, the execvp() call in the function at the bottom gets me the following:

o-shell.c:128: warning: passing arg 2 of `execvp' from incompatible pointer type

I know for sure i'm calling execvp incorrectly, any tips/pointers would be great. I want to use /bin/cat followed by filename as the argument.

Code:

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <string.h>

int main(int argc, char *argv[])
{
	//VARIABLE DECLARATIONS

	char command[50];				//Command line input

	//tokens for strtok() funtion
	char * com;						//Primary command
	char * arg1;					//First argument of command (usually a file name)
	char * arg2;					//2nd argument of command (usually a file name)

	int args;						//Number of arguments entered

	//FUNCTION DECLARATIONS

	void typefile(char * filename);

	printf("***************************************************\n");
	printf("Welcome to O-Shell! A UNIX shell by O Haqqi\n\n");
	printf("Type 'help' for list of commands, 'exit' to exit\n");
	printf("***************************************************\n");

	for(;;)
	{

	printf("o-shell>");						//user prompts for o-shell

	fgets(command, 1024, stdin);		//command line input from user

	com = strtok(command, " \r\n\t");

	args = 0;
	arg1 = strtok(NULL, " \r\n\t");
	if(arg1) args++;						//to see if arguments being tracked
	arg2 = strtok(NULL, " \r\n\t");
	if(arg2) args++;						//to see if arguments being tracked

	if(com != NULL)			//Can only execute commands if a command is entered
							//Otherwise it keeps looping and printing prompt
	{
	printf("command entered: %s\n", com);
	printf("There are %d arguments\n", args);

	if ((strcmp(com,"help")) == 0 || (strcmp(com,"Help")) == 0)
	{
		printf("***************************************************\n");
		printf("\nO-Shell Help Menu:\n");
		printf("\nhelp - Print help menu\n");
		printf("\nexit - Exit O-Shell\n");
		printf("\ntype <file> - Print contents of <file> to terminal\n");
		printf("\ncopy <file1> <file2> - Copy contents of <file1> to <file2>.");
		printf("\n     <file2> must be a non-existent file and will be created\n");
		printf("\ndelete <file> - Delete <file> from system\n");
		printf("***************************************************\n");
	}

	else if ((strcmp(com,"exit")) == 0 || (strcmp(com,"Exit")) == 0)
	{
		printf("Exiting O-Shell...Goodbye!\n");

		//if exit command is entered, exit() system call is performed
		exit(1);
	}

	else if ((strcmp(com,"type")) == 0 || (strcmp(com,"Type")) == 0)
	{
		if((arg1 == NULL) || (arg2 != NULL))		//arg1 must exist, arg2 must be empty
		{
			printf("Incorrect number of arguments! Type 'help' for correct format.\n");
		}

		else
		printf("Printing contents of file: %s\n", arg1);
		printf("***************************************************\n");

		typefile(arg1);			//call typefile function (see below)
	}

	else
	printf("Invalid command!!! Type 'help' for list of valid commands.\n");

	}

	}

	return 0;
}

/************************************************************************************************
Function typefile() prints contents of a file to the terminal
Format: type <file1>
************************************************************************************************/

void typefile(char * filename)
{
	int pid, status;

	const char cat[] = "/bin/cat";

	pid = fork();

	if(pid < 0)
	printf("ERROR: Child pid = %i FORK FAILED! Please try again.\n", pid);

	else if(pid > 0)
	printf("ERROR: Child pid = %i Parent process executing, FORK FAILED!\n", pid);

	else if(pid == 0)				//If the process id is zero, fork() was successful
	{
		printf("Child pid = %i FORK SUCCESSFUL...\n");

		execvp(cat, filename);
	}

}

 

Do you see yourself conforming to that?