User guide

3.3. GLOBAL FUNCTIONS 61

selectoutput(scb) CIN:y, POS:y, NAT:y

This r ou ti ne selects scb as the currently selected output stream. It aborts (with

code 187) if scb is not an output stream.

res := setbit(bitno, bitvec, state) CIN:y, POS:y, NAT:y

This function sets the speci ﬁe d bit in bitvec t o 1 or 0 depending on whether state

is TRUE or FALSE, respectively. It returns a non-zero value if and only if the previous

setting of the bit was a one. See testbit below.

res := setflags(taskid, flags) CIN:n, POS:y, NAT:n

This Cintpos function sets the speciﬁed ﬂags in the task control block of the speciﬁed

task. If successful it returns a non zero value with result2 set to the previous setting

of the ﬂags ﬁeld, otherwise it returns zero with result2 set to 101 indivating that

taskid was invalid. For more information about ﬂags see testflags descri bed b e l ow.

oldse ed := setlogname(logname, logvalue) CIN:y, POS:y, NAT:y

This sets the value of logical variable logname to the logvalue. By convention

logvalue should be a string. The list of logical name-value pairs is held in the root

node.

oldse ed := setseed(newseed) CIN:y, POS:y, NAT:y

The c ur r ent seed can be set to newseed by the call setseed(newseed). This function

returns the previous seed val ue .

srchwk(tcb) CIN:n, POS:y, NAT:n

This function is the Cintpos scheduler which is normally only called from within

one of the klib library functions or from the interrupt service routine. Its argument

points to the highest pri or i ty task control block that could possibly run. It searches

down the priority chain from this p oi nt until it ﬁnds the highest priority runnable task.

After setting the globals tcb and taskid appropriately, it gives t hi s task control using

a call of sys(Sys

rti,...).

code := start(a1, a2, a3, a4) CIN:y, POS:y, NAT:y

This function is, by convention, the mai n function of a program. If it is called from

the command language interpreter (see section 4), its ﬁrst argument is zero and i t s

result should be the command completion code; however, if it is the main function of

a module run by callseg, deﬁned below, then it can take up to 4 arguments and its

result is up to the user. By convention, a command complet i on code of zero indicates

successful completion and large r numbers indicate errors of ever gre ate r severity

res := stepstream(scb, n) CIN:y, POS:y, NAT:y

This function advances the position of stream scb by n words, returning TRUE if

successful, and FALSE otherwise.

stop(code, reason) CIN:y, POS:y, NAT:y

This function is provided to stop the execution of the curr e nt command running

under control of the CLI. The arguments code and reason are placed in the CLI globals