Thread: stdlib.h system()

This question is about the funtion system in stdlib.h

I'm utilising the unix command file from within a c program

all the command does is tell whether or not an item is a file or not

my question is whether or not it is possible to run this in the background rather than in the terminal

by this i mean, I don't want the information about whether or not something is a file to go to the terminal, I want to store it in a variable.

I know that system will return an integer value based on whetehr the command ran or not, but I need a specific value as returned, to terminal or otherwise, to be stored in a variable within my program.

any ideas?

Couldn't you just go like this:

Code:

FILE *f1 = fopen(item);
if(!f1)
    puts("The item is not a file");
fclose(f1);
f1 = NULL;

that does make sense actually

thanx

Originally Posted by Kleid-0

Couldn't you just go like this:

Code:

FILE *f1 = fopen(item);
if(!f1)
    puts("The item is not a file");
fclose(f1);
f1 = NULL;

So when fopen() fails, what does fclose(NULL)?

Code:

FILE *f1 = fopen("file_path");
if(!f1) {
    printf("The item is not a file");
} else {
 printf("File exists!"); 
 fclose(f1);
}

Happy?
[/CODE]

Q - does that apply universally?

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FWIW - it's usually good practice to set a pointer to NULL when you know you're done with it. Causes fewer really puzzling problems (other than a GPF or segfault) later on if you inadvertantly try to use it again.

Also in the unix world when you only want to determine a file's existence and you don't plan on really opening it, a better choice is to call stat(). This is because stat only fiddles with the file system, and doesn't go through a lot of mumbo-jumbo creating kernel mode data structures if the file does exist.

I don't know what Windows does now, but for 16 bit windows pretending to be 32 bit, stat() was the better choice too.
[/blah]

Originally Posted by quzah

You seem to be under the impression that we care if you know how to fix some one else's code. We don't.

The care bears care! lol