# %semop() function

The %semop() function performs an array
of semaphore operations on a set of semaphores.

**For Windows:**Not Supported

## Syntax

```
code = %semop(sem-ID, sops, num)
```

## Parameter(s)

| sem-ID | Semaphore identifier returned by a call to %semget(). |
| --- | --- |
| sops | Array of semaphores operation. sops is a number by 3 two-dimensional arrays. Each row in the array is the equivalent of a sops structure, as defined in the UNIX system documentation. In other words, sops ( i ,1) is sem_num, sops ( i ,2) is sem_op, sops ( i ,3) is sem_flg. See the UNIX system documentation for the description of these fields. |
| num | Number of rows in the sops array. |
Note: The elements of the *sops* array are
integers, instead of short integers, as the regular `libc.a` call.

## Example(s)

```
include dm,bp,unix.h ipc.h
include dm,bp,unix.h sem.h
include dm,bp,unix.h mode.h
* Get a set of 4 semaphores
sem-ID=semget(key, 4, ipc$creat)
if sem-ID<0 then
 crt "semget error=":system(0)
 stop
end
* Wait for: (1st sem >=1) and (2nd sem >=2)
dim sops(2,3)
* - Set 1st condition
sops(1,1)=0 ;* 1st sem
sops(1,2)=-1 ;* Wait until can do -1
sops(1,3)=0 ;* No flag
* - Set 2nd condition
sops(1,1)=1 ;* 2nd sem
sops(1,2)=-2 ;* Wait until can do -2
sops(1,3)=0 ;* No flag
n=semop(sem-ID, sops, 2)
if n<0 then
 crt "semop error=":system(0)
 stop
end
```

## See also

- [%semctl() function](https://d3codex.com/pickbasic-flashbasic/percent-semctl-function/)
- [%semget() function](https://d3codex.com/pickbasic-flashbasic/percent-semget-function/)

---
Source: https://d3codex.com/pickbasic-flashbasic/percent-semop-function/ - part of the D3Codex reference.