Replace exactly match of a number

[Tambaa Hapa]

I am trying to replace a number with some string. For example, replace &1
with hello. However using s/&$num/hello/g where $num = 1 also replaces &10
to hello0. Anyone have any ideas on how to do this?

Thanks in advance
TH

 

[A. Sinan Unur]

I am trying to replace a number with some string. For example, replace
&1 with hello. However using s/&$num/hello/g where $num = 1 also
replaces &10 to hello0. Anyone have any ideas on how to do this?

Isn't it a little too tedious to write your own templating system?

 

[Dave Weaver]

I am trying to replace a number with some string. For example, replace &1
with hello. However using s/&$num/hello/g where $num = 1 also replaces &10
to hello0. Anyone have any ideas on how to do this?

s/&$num(?!\d)/hello/g;

see "perldoc perlre" for details.

 

[Paul Lalli]

I am trying to replace a number with some string. For example, replace &1
with hello. However using s/&$num/hello/g where $num = 1 also replaces &10
to hello0. Anyone have any ideas on how to do this?

How about making sure the next thing is not a digit?

s/&$num(?!\d)/hello/g;

Read more about look-ahead assertions in:
perldoc perlre
perldoc perlretut
and probably one or two others I'm forgetting.

Paul Lalli

 

[Tambaa Hapa]

Thanks a bunch Dave. That certainly did the trick. I guess I just needed a
little imagination!

TH

 

[Tambaa Hapa]

Thanks Paul. I could not figure out how to do the look ahead. I tried
something like s/&$num[^\d]/hello/g but that replaced the next character
too, which is not what I wanted. Your suggestion (and Dave's) did the trick.
Thanks again.

TH

 

[Eric Bohlman]

Thanks Paul. I could not figure out how to do the look ahead. I tried
something like s/&$num[^\d]/hello/g but that replaced the next
character too, which is not what I wanted. Your suggestion (and
Dave's) did the trick. Thanks again.

I would, though, seriously take up Sinan's suggestion and go over to
http://search.cpan.org and search for "template"; there are tons of
excellent template-substitution modules and you might save yourself hours
of wheel-reinvention.