help w/ while (or other better for this)

hi.

i have a file "temp" just to store a number

every time a x key is pressed, the number in file increase +1, and every time a y key is pressed, the number in file decrease -1, until 0 (0 is the minimal)

this part is working.

whats left:
when the number in the file change from 1 to 0 the program must to execute a system command (a shellscript) and when the number in the file change from 0 to 1 the program must to execute another system command

the scripts only must be executed when the number change from 0 to 1 and from 1 to 0 (not when change from 1 to 2, 3 > 4, 4 > 5, etc)

but i dont know the best way to do this...

if num == 0
if num == 1
How is that hard?

Can you describe your problem in more detail? Are you supposed to write a program which monitors this file, looking for changes from 0->1 or 1->0, and react accordingly?

yes, but isnt a program just for this, this must be a function inside the normal program.

A function to monitor this file, looking for changes from 0->1 or 1->0, and react accordingly.

In the same time the file change the content from 0->1, the program must to execute a system() to execute a shellscript, and in the same time the file change the content from 1->0, the program must to execute a system() to execute another shellscript

Yes, and what part of this is it that you are not able to do?

--
Mats

Quote:

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Originally Posted by matsp

Yes, and what part of this is it that you are not able to do?

--
Mats

---

this:

Quote:

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A function to monitor this file, looking for changes from 0->1 or 1->0, and react accordingly.

In the same time the file change the content from 0->1, the program must to execute a system() to execute a shellscript, and in the same time the file change the content from 1->0, the program must to execute a system() to execute another shellscript

---

something like this:

Code:

---

infinite loop{
 num='cat ./num'
  if num == 0
  system("./script1");
  if num == 1
  system("./script2");
}

---

or

Code:

---

infinite loop{
 read file ./num
  if content of num == 0
  system("./script1");
  if content of num == 1
  system("./script2");
}

---

You will need some kind of delay in your infinite loop or this will max your CPU out, which will have very negative and noticeable effects.

Read up on sleep() or nanosleep().

So, why don't you try to write a C program that does what you have just described in some sort of shell-script like way.

--
Mats