execline
Software
skarnet.org

The elgetpositionals program

elgetpositionals substitutes the positional parameters of an execline script.

Interface

     elgetpositionals [ -P sharp ] prog...

• elgetpositionals reads the number n of "positional parameters" in the # environment variable. If that variable is not set or does not contain a valid n, elgetpositionals exits 100.
• elgetpositionals performs some substitutions in parallel on prog...:
  • key: #, value: n
  • key: 0, value: the value of the 0 environment variable
  • key: 1, value: the value of the 1 environment variable
  • ... and so on until n (or sharp if it is greater than n). Those values are never transformed.
  • key: @, value: all values of the variables from 1 to n. This value is split into n words.
  If a variable between 0 and n does not exist, elgetpositionals exits 100.

Options

• -P sharp : substitute at least sharp+1 positional parameters, from 0 to max(n, sharp). If n<sharp, positional parameters between n+1 and sharp are replaced with the empty string. Not having the -P switch is equivalent to having -P 0.

Notes

• A typical argument-taking execline script will often begin that way:

   #!/command/execlineb
   elgetopt optstring
   elgetpositionals
   prog...
  

• If you are performing other substitutions that do not depend on the positional parameters, think about replacing the elgetpositionals call with a multisubstitute call containing the elgetpositionals directive.
• If you are going to use the shift command, it is best to use importas to substitute the first positional parameters, then use shift, then elgetpositionals. That way, $@ will correctly be replaced by the remaining arguments. More generally, you should try to use elgetpositionals as late as possible.
• Use execlineb's -S switch instead of elgetpositionals whenever you can. It is more efficient.