Thread: question about system commands

The function 'system()' only takes one string as an argument.

Look into sprintf.

from what I read that doesn't help me.. it said that it converts numbers into a string of text? so I'm not saying your wrong but I guess I am asking how I could use it here?

Originally Posted by alexnb185

from what I read that doesn't help me.. it said that it converts numbers into a string of text? so I'm not saying your wrong but I guess I am asking how I could use it here?

The 'sprintf()' function allows you to use format specifiers from the printf family(%s, %d, and so on) but instead of printing it to the screen, print it to an array. This benefits you, because:

Code:

// ..

char name_of_file[] = "lolomg.txt", empty_array[50];

sprintf(empty_array, "notepad %s", name_of_file);

puts(empty_array);

// ...

If you execute this bit of code, you'll see how it helps you.

I am just using gcc to compile under leopard

Originally Posted by Adak

In your program, scanf() is going to need the address of operator '&', added to it, so app is set up properly.

System() is passed a literal, it's not like printf(), and won't substitute the value of app for %s, (even if app is set up properly).

Does your compiler support a system() function that can be passed something else, besides a string literal?

An array does not need the address operator before it when passed to scanf or other input functions. Passing an array like that passes a pointer to the first element of it, eg, the address of the array. So, long story short, no need for it.

I believe IceDane's post about using sprintf(), is your answer. Play around with his code and see if you don't agree.

ok, I compiled that code Icedane. What happened was it printed "notepad lolomg.txt" But I don't see how I can use that if the system() function won't let you put in strings.. or is it possible to do this

Code:

.....
system(empty_array);
......

and it would send "notepad lolomg.txt" to the sytem?

and the answer is yes.. it did do that