In your second example, it looks like you have an escape character before the first ‘dot’, but not the second one. Is this a typo, or am I misunderstanding the command?
It’s not a typo. The first section of the regex is a matching section, where a dot means “match any character”, and an escaped dot is a literal dot character. The second section is the replacement section, and you don’t have to escape the dot there because that section isn’t matching anything. You can escape it though if it makes the code easier to read.
rename is written in Perl so all Perl regular expression syntaxes are valid.
However, your comment did make me realize that I hadn’t escaped my dot in the third example! So I fixed that.
Check out
rename$ touch foo{1..5}.txt $ rename -v 's/foo/bar/' foo* foo1.txt renamed as bar1.txt foo2.txt renamed as bar2.txt foo3.txt renamed as bar3.txt foo4.txt renamed as bar4.txt foo5.txt renamed as bar5.txt $ rename -v 's/\.txt/.text/' *.txt bar1.txt renamed as bar1.text bar2.txt renamed as bar2.text bar3.txt renamed as bar3.text bar4.txt renamed as bar4.text bar5.txt renamed as bar5.text $ rename -v 's/(.*)\.text/1234-$1.txt/' *.text bar1.text renamed as 1234-bar1.txt bar2.text renamed as 1234-bar2.txt bar3.text renamed as 1234-bar3.txt bar4.text renamed as 1234-bar4.txt bar5.text renamed as 1234-bar5.txtSED combinator, you win 🙌
In your second example, it looks like you have an escape character before the first ‘dot’, but not the second one. Is this a typo, or am I misunderstanding the command?
It’s not a typo. The first section of the regex is a matching section, where a dot means “match any character”, and an escaped dot is a literal dot character. The second section is the replacement section, and you don’t have to escape the dot there because that section isn’t matching anything. You can escape it though if it makes the code easier to read.
renameis written in Perl so all Perl regular expression syntaxes are valid.However, your comment did make me realize that I hadn’t escaped my dot in the third example! So I fixed that.