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There is more to this than just one small example of code can fix. I found a pretty complete discussion here. READ the whole thing because there are several gotchas.
Try:


Malloc and MPI...

The 8085 uses 2s complement to represent negative numbers...so knowing that negate i^2 by inverting it and adding 1 to it followed by adding 1 again to represent the equation "n=1-i^2"...and in the...

As the 8085 doesnt have a multiply instruction you will have to add i to itself i times every time you go throgh the loop...here is a sample routine when i==3...

MVI B,03H
MVI A,0H
MOV...

These macros are used to check process status. The pclose() call does report exit status of the process which has been run by corresponding popen().


int rc;
rc = pclose(pfp);...

don't forget to use W macros (WEXITSTATUS , etc...) when checking return status of pclose

Because it's completely possible for a program to print more than one line. ;) fgets() just reads the lines one at a time. Inside the loop, you can use the contents of the line as you see fit.
...

char buf[512];
FILE *fp=popen("ls -l", "r");

while(fgets(fp, 512, fp))
{
...
}

pclose(fp);

na and sur are not type char - they're char pointers to 20 bytes of memory.

You cant do free(Stus.arr) because Stus is now a type...first you have to create an object of type Stus...
Stus x;
Now you can refer to to its member arr using this...
free(x.arr)

No, you cannot just place it into a loop because there is no way to 'mark' the buffer and start sscanf where it left off. You can do something like this:



#include <string.h>
#include...

They were probably making an array of pointers to strings.

Great progress!

You need to correct a few things if you haven't.

First, the warning about %s in conjunction with strerror() is because you haven't included string.h. The strerror() function...

I found another problem:

You're allocating size*sizeof(struct shop *).

What is a shop *? It's a pointer -- something like an integer, to hold one single memory address. It might be 4 bytes,...

Windows can let you get away with some very silly things -- for a while. In my early programming days I wrote a music player that crashed on quit, and I couldn't figure out why until I rewrote it...

Because your parent process waits for the child to exit, all data will be read into the buffer, and you'll need to pull all of the values out in a single sscanf() call.

Something like this:


...

See my comments in red above...it needs more fixes but that is left as an exercise for the op...

I've made changes to your code, and have a working copy. I'll post my comments so if you want to work the changes yourself you can; I can post the code if you'd rather me do that.

In no real...

There are many things wrong with the pipe and array code...not initalizing m[4] to 0 before using it in the addition and in the parent you are not reading the value into c[i][j] but instead putting...

Only have time for a quick look, but this is what jumped out at me:

Write is not like printf(), it takes a buffer of data and a length and doesn't do any formatting. You had the right idea in...

First, move your initialisation of m to the start of the loop:



for(j=0;j<4;j++)
{
m = 0;
for(n=0;n<3;n++)
{
m=m+a[i][n]*b[n][j];
}
c[i][j]=m;
}
...

As explained many times in the last 2 pages, that sets all three arrays to the SAME MEMORY. It doesn't matter where you put that wrong code, it doesn't make it right code.

int *A=shmat(...);
int...

You use a(i,j) in many places you should be using A(i,j).

That's mutually exclusive.

If they're fixed in size, they don't change and therefore can't be set at runtime.

That won't work. l, m, n have to be constant numbers. That's why I asked whether...

Well, it depends... Are these arrays going to change in size, at all, ever? Or are they going to be a fixed size, forever?

If they're going to be the same size forever, you can do this:
struct...

It's the same as B = A + (3*2). Just reusing my code. shmat() always gives you the same memory for the same ID -- that's what lets you share it between processes, you get the same memory.

//...