This is based on An Introductory User’s Guide to IRAF Scripts by Ed Anderson.
You will recall that several tasks may be called in sequence on a
single command line, using a semicolon ; to separate each command.
For example:
cl> mkdir database; dir; cd database; dir
database
no files found
If the command sequence is too long to fit on a single line, one could
construct a compound statement by using the curly braces, {}:
cl> {
>>> dir
database
>>> cd database
>>> dir
no files found
>>> }
The >>> prompt indicates that the CL requires more input (in this
case, the CL is waiting for a }) before executing the task or
sequence of tasks. A Terminal Script is essentially a compound
statement, but uses some of the simple programming tools provided by
the CL.
Now we check some control structures. First create a list file with a
for loop
File: loop.cl
for (i = 1; i < 5; i+=1) {
j = i*i
print (i, j, >> "sqr.lis")
}
Execute this script and check the content of the list:
cl> cl < loop.cl
cl> type "sqr.lis"
1 1
2 4
3 9
4 16
Read the file just created with a while loop with this script:
File: while.cl
list = "sqr.lis"
while (fscan(list, i, j) != EOF) print(i, j)
cl> cl < while.cl
1 1
2 4
3 9
4 16
Test intrinsic mathematical CL functions
Test options: decimals=7
cl> =sin(1.2)
0.9320390859672263
cl> =cos(1.2)
0.3623577544766736
cl> =tan(1.2)
2.5721516221263188
cl> =atan2(2.,3.)
0.5880026035475675
cl> =exp(1.2)
3.3201169227365472
cl> =frac(1.2)
0.2
cl> =int(-1.2)
-1
cl> =log(1.2)
0.1823215567939546
cl> =log10(1.2)
0.07918124604762482
cl> =max(2,3,4,2)
4
cl> =min(2,3,4,2)
2
cl> =mod(123, 7)
4
cl> =nint(1.5)
2
cl> =nint(2.5)
3
cl> =sqrt(1.2)
1.0954451150103321
Intrinsic logic functions
cl> =real("1.23")
1.23
cl> =isindef(0)
no
cl> =isindef(INDEF)
yes
cl> =radix(123, 10)
123
cl> =radix(123, 16)
7B
cl> =radix(-123, 10)
4294967173
cl> =radix(-123, 16)
FFFFFF85
Intrinsic string functions
cl> =stridx("fd", "abcdefg")
4
cl> =strldx("fd", "abcdefg")
6
cl> =strlen("abcdefg")
7
cl> =strlstr("def", "abcdefg")
4
cl> =strlwr("aBcDeF")
abcdef
cl> =strstr("def", "abcdefg")
4
cl> =strupr("aBcDeF")
ABCDEF
cl> =substr("abcdefg", 2, 5)
bcde