Idiomatic write

ruby-talk
1

Hi,

I want to search for a pattern in a file, replace it with something and
then write it back to the file. In the shell-script idiom,
I’d do:

sed /pattern/replace myfile > tmpfile
mv tmpfile myfile

In Ruby, I could do the same thing, slurp the file into a string and then
write it back again. I was wondering if there’s a more idiomatic way of
doing it, in place, i.e., edit the file straight away. This could probably
be more practical when the file to be edited is a huge one…

Any pointers(sic)…

regs
Vivek

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2

Hi,

Vivek Nallur nvivek@konark.ncst.ernet.in writes:

I want to search for a pattern in a file, replace it with something and
then write it back to the file. In the shell-script idiom,
I’d do:

sed /pattern/replace myfile > tmpfile
mv tmpfile myfile

In Ruby, I could do the same thing, slurp the file into a string and then
write it back again. I was wondering if there’s a more idiomatic way of
doing it, in place, i.e., edit the file straight away. This could probably
be more practical when the file to be edited is a huge one…

Any pointers(sic)…

% ruby -i~ -pe ‘gsub(/pattern/, “replace”)’ myfile

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eban

3

WATANABE Hirofumi graced us by uttering:

Vivek Nallur nvivek@konark.ncst.ernet.in writes:

I want to search for a pattern in a file, replace it with something and
then write it back to the file. In the shell-script idiom,
I’d do:

sed /pattern/replace myfile > tmpfile
mv tmpfile myfile

In Ruby, I could do the same thing, slurp the file into a string and then
write it back again. I was wondering if there’s a more idiomatic way of
doing it, in place, i.e., edit the file straight away. This could probably
be more practical when the file to be edited is a huge one…

Any pointers(sic)…

% ruby -i~ -pe ‘gsub(/pattern/, “replace”)’ myfile

Does this work if /pattern/ spans lines?

Tim Hammerquist

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We all know linux is great…it does infinite loops in 5 seconds.
– Linus Torvalds