Question

I know, I know, I should use a modern shell… Anyway, so here is the alias:

  alias p4client echo `p4 info | perl -ne 's/Client name: (.*)$/print $1/e'` 

I also know there is probably a better way to get the p4 client name. This is just an example. So, can anyone tell me a nice and clean way to get this to evaluate this when I invoke the alias rather than evaluating when the alias is created?

Answer 1

The only trick is backslash escaping the single quotes and surrounding everything else with single quotes:

alias p4client 'echo `p4 info | perl -ne '\''s/Client name: (.*)$/print $1/e'\''`'

Though the perl can be simplified:

alias p4client 'echo `p4 info | perl -ne '\''print /Client name: (.*)/'\''`'

and the echo and “ are saying capture the output these commands print and print it; just print the output instead (only having perl include the newline instead of stripping it from the p4 output only to have echo re-add it):

alias p4client 'p4 info | perl -ne '\''print /Client name: (.*)/s'\'

though now there’s nothing double-quote-unfriendly left in there, so:

alias p4client "p4 info | perl -ne 'print /Client name: (.*)/s'"

There’s nothing different here from how you would do it in bash except not having an = after p4client.