Exclamation marks in foreach loops

[Elmer Villanueva]

Hello, everyone.

I'd like some advice, please.

I've come across some code by both Brendan Halpin and Alan Riley. It's the second ever posting on this section of the Forum. The code by Brendan is:

foreach topic in topic1 topic2 topic3 {    
     translate `topic'.sthlp `topic'.ps, translator(smcl2ps) replace header(off) logo(off) pagesize(A4)    
     !ps2pdf `topic'.ps    
     !rm `topic'.ps
}

and Alan's response is

foreach topic in topic1 topic2 topic3 {    
     translate `topic'.sthlp `topic'.ps, translator(smcl2ps) replace header(off) logo(off) pagesize(A4)    
     !ps2pdf `topic'.ps    
     !rm `topic'.ps
}

My question relates to the use of the exclamation mark in the second and third lines of the -foreach- loop.

!ps2pdf `topic'.ps    
!rm `topic'.ps

Can someone point me to documentation about the symbol's function? I've trawled through the Stata documentation and the web with more than enough false positive hits.

Thanks.

[Nick Cox]

help shell

[Elmer Villanueva]

Brilliant.

Thanks, mate.