Objective
Change these filenames:
to these filenames:
Shell Code
To test:
ls F00001-0708-*|sed 's/\(.\).\(.*\)/mv & \1\2/'
To perform:
ls F00001-0708-*|sed 's/\(.\).\(.*\)/mv & \1\2/' | sh
My Question
I don't understand the sed code. I understand what the substitution command
$ sed 's/something/mv'
means. And I understand regular expressions somewhat. But I don't understand what's happening here:
\(.\).\(.*\)
or here:
& \1\2/
The former, to me, just looks like it means: "a single character, followed by a single character, followed by any length sequence of a single character"--but surely there's more to it than that. As far as the latter part:
& \1\2/
I have no idea.
This question is related to
bash
shell
sed
file-rename
Using perl rename (a must have in the toolbox):
rename -n 's/0000/000/' F0000*
Remove -n
switch when the output looks good to rename for real.
There are other tools with the same name which may or may not be able to do this, so be careful.
The rename command that is part of the util-linux
package, won't.
If you run the following command (GNU
)
$ rename
and you see perlexpr
, then this seems to be the right tool.
If not, to make it the default (usually already the case) on Debian
and derivative like Ubuntu
:
$ sudo apt install rename
$ sudo update-alternatives --set rename /usr/bin/file-rename
For archlinux:
pacman -S perl-rename
For RedHat-family distros:
yum install prename
The 'prename' package is in the EPEL repository.
For Gentoo:
emerge dev-perl/rename
For *BSD:
pkg install gprename
or p5-File-Rename
For Mac users:
brew install rename
If you don't have this command with another distro, search your package manager to install it or do it manually:
cpan -i File::Rename
Old standalone version can be found here
This tool was originally written by Larry Wall, the Perl's dad.
If all you're really doing is removing the second character, regardless of what it is, you can do this:
s/.//2
but your command is building a mv
command and piping it to the shell for execution.
This is no more readable than your version:
find -type f | sed -n 'h;s/.//4;x;s/^/mv /;G;s/\n/ /g;p' | sh
The fourth character is removed because find
is prepending each filename with "./".
for i in *; do mv $i $(echo $i|sed 's/AAA/BBB/'); done
The easiest way would be:
for i in F00001*; do mv "$i" "${i/F00001/F0001}"; done
or, portably,
for i in F00001*; do mv "$i" "F0001${i#F00001}"; done
This replaces the F00001
prefix in the filenames with F0001
.
credits to mahesh here: http://www.debian-administration.org/articles/150
The sed
command
s/\(.\).\(.*\)/mv & \1\2/
means to replace:
\(.\).\(.*\)
with:
mv & \1\2
just like a regular sed
command. However, the parentheses, &
and \n
markers change it a little.
The search string matches (and remembers as pattern 1) the single character at the start, followed by a single character, follwed by the rest of the string (remembered as pattern 2).
In the replacement string, you can refer to these matched patterns to use them as part of the replacement. You can also refer to the whole matched portion as &
.
So what that sed
command is doing is creating a mv
command based on the original file (for the source) and character 1 and 3 onwards, effectively removing character 2 (for the destination). It will give you a series of lines along the following format:
mv F00001-0708-RG-biasliuyda F0001-0708-RG-biasliuyda
mv abcdef acdef
and so on.
Some examples that work for me:
$ tree -L 1 -F .
.
+-- A.Show.2020.1400MB.txt
+-- Some Show S01E01 the Loreming.txt
0 directories, 2 files
## remove "1400MB" (I: ignore case) ...
$ for f in *; do mv 2>/dev/null -v "$f" "`echo $f | sed -r 's/.[0-9]{1,}mb//I'`"; done;
renamed 'A.Show.2020.1400MB.txt' -> 'A.Show.2020.txt'
## change "S01E01 the" to "S01E01 The"
## \U& : change (here: regex-selected) text to uppercase;
## note also: no need here for `\1` in that regex expression
$ for f in *; do mv 2>/dev/null "$f" "`echo $f | sed -r "s/([0-9] [a-z])/\U&/"`"; done
$ tree -L 1 -F .
.
+-- A.Show.2020.txt
+-- Some Show S01E01 The Loreming.txt
0 directories, 2 files
$
2>/dev/null
suppresses extraneous output (warnings ...)
reference [this thread]: https://stackoverflow.com/a/2372808/1904943
The backslash-paren stuff means, "while matching the pattern, hold on to the stuff that matches in here." Later, on the replacement text side, you can get those remembered fragments back with "\1" (first parenthesized block), "\2" (second block), and so on.
ls F00001-0708-*|sed 's|^F0000\(.*\)|mv & F000\1|' | bash
Here's what I would do:
for file in *.[Jj][Pp][Gg] ;do
echo mv -vi \"$file\" `jhead $file|
grep Date|
cut -b 16-|
sed -e 's/:/-/g' -e 's/ /_/g' -e 's/$/.jpg/g'` ;
done
Then if that looks ok, add | sh
to the end. So:
for file in *.[Jj][Pp][Gg] ;do
echo mv -vi \"$file\" `jhead $file|
grep Date|
cut -b 16-|
sed -e 's/:/-/g' -e 's/ /_/g' -e 's/$/.jpg/g'` ;
done | sh
you've had your sed explanation, now you can use just the shell, no need external commands
for file in F0000*
do
echo mv "$file" "${file/#F0000/F000}"
# ${file/#F0000/F000} means replace the pattern that starts at beginning of string
done
The parentheses capture particular strings for use by the backslashed numbers.
I wrote a small post with examples on batch renaming using sed
couple of years ago:
http://www.guyrutenberg.com/2009/01/12/batch-renaming-using-sed/
For example:
for i in *; do
mv "$i" "`echo $i | sed "s/regex/replace_text/"`";
done
If the regex contains groups (e.g. \(subregex\
) then you can use them in the replacement text as \1\
,\2
etc.
Source: Stackoverflow.com