Thread: Character Array: If Null

Hi,

Im having a really simple problem.
I have an if statement to check if an input from a user is empty or not, if it is then the program needs to take one course of action. if it isnt then it uses it.

Its a prompt for a filename to save some variables to, reading into a character array[20] called filename, I will be changing from gets to something else shortly but I want to get the if statement working first.

Code:

printf("Enter filename");
gets(filename);

if(filename == NULL)
{
savefile = fopen("default.dat","w");
}
else
{
savefile = fopen(filename, "w");
}

now before I had the option to enter a filename it automatically it would save to default.dat with that exact same line. Now it doesnt seem to register that filename is null when I dont input anything.
Is this because its an array so I cant use a simple if == Null statement?

or, because its picking up some random place in memory its never actually empty?

Thanks for any pointers.

looking at you code i have found some bugs
1. shouldn't use gets to read a string read FAQ for more information for not using gets instead use fgets

syntax for fgets

Code:

fgets(char *, int, FILE *);

and your actual problem, try out the follwing code

Code:

char file[20];

printf("Enter the file name\n?");
fgets(file,sizeof file, stdin);

if(file[0]=='\0')
       fp=fopen(default.dat,"w");
else
      fp=fopen(file,"w");

hope this helps

s.s.harish

Thats great thanks