Replace first character of file in folder from Uppercase to Lower case - macos

I'm trying to convert 3,000 or so .svg files from CapitalCase to camelCase.
Current:
-Folder
--FileName1
--FileName2
--FileName3
Goal:
-Folder
--fileName1
--fileName2
--fileName3
How can I use terminal to change the casing on the first character with to lowercase?
Currently I've been trying something along these lines: for f in *.svg; do mv -v "$f" "${f:1}"; done
All files in the folder start with a letter or number.

This can be done very succinctly in zsh with zmv:
autoload zmv
zmv -nvQ '(**/)(?)(*.svg)(.)' '$1${(L)2}$3'
This will recurse through any number of directory levels, and can handle name collisions and other edge cases.
Some of the pieces:
-n: no execution. With this option, zmv will only report what changes it would make. It's a dry run that can be used to test out the patterns. Remove it when you're ready to actually change the names.
-v: verbose.
-Q: qualifiers. Used to indicate that the source pattern includes a glob qualifier (in our case (.)).
'(**/)(?)(*.svg)(.)': source pattern. This is simply a regular zsh glob pattern, divided into groups with parentheses. The underlying pattern is **/?*.svg(.). The pieces:
(**/): directories and subdirectories. This will match any number of directory levels (to only affect the current directory, see below).
(?): matches a single character at the start of the file name. We'll convert this to lowercase later.
(*.svg): matches the rest of the file name.
(.): regular files only. This is a zsh glob qualifier; zmv recognizes it as a qualifier instead of a grouping because of the -Q option. The . qualifier limits the matching to regular files so that we don't try to rename directories.
'$1${(L)2}$3': destination pattern. Each of the groupings in the source pattern is referenced in order with $1, $2, etc.
$1: the directory. This could contain multiple levels.
${(L)2}: The first letter in the file name, converted to lowercase. This uses the L parameter expansion flag to change the case.
The l expansion modifier will also work: $2:l.
The conversion can handle non-ASCII characters, e.g. Éxito would
become éxito.
$3: the rest of the file name, including the extension.
Variations
This will only change files in the current directory:
zmv -nv '(?)(*.svg)' '$1:l$2'
The source pattern in the following version will only match files that start with an uppercase letter. Since the zmv utility won't rename files if the source and destination match, this isn't strictly necessary, but it will be slightly more efficient:
zmv -nvQ '(**/)([[:upper:]])(*.svg)(.)' '$1${(L)2}$3'
More information
zmv documentation:
https://zsh.sourceforge.io/Doc/Release/User-Contributions.html#index-zmv
zsh parameter expansion flags:
https://zsh.sourceforge.io/Doc/Release/Expansion.html#Parameter-Expansion-Flags
Page with some zsh notes, including a bunch of zmv examples:
https://grml.org/zsh/zsh-lovers.html

Solving in bash, tested and working fine, be careful though with your files you working on.
Renaming files in current directory where this script is (1st arg then'd be .) or provide a path, it's do lower-casing of the first letter, if it was uppercase, and yet nothing if it was a number, argument must be provided:
# 1 argument - folder name
# 2 argument - file extension (.txt, .svg, etc.)
for filename in $(ls "$1" | grep "$2")
do
firstChar=${filename:0:1}
restChars=${filename:1}
if [[ "$firstChar" =~ [A-Z] ]] && ! [[ "$firstChar" =~ [a-z] ]]; then
toLowerFirstChar=$(echo $firstChar | awk '{print tolower($0)}')
modifiedFilename="$toLowerFirstChar$restChars"
mv "$1/$filename" "$1/$modifiedFilename"
else
echo "Non-alphabetic or already lowercase"
# here may do what you want fith files started with numbers in name
fi
done
Use: bash script.sh Folder .txt
ATTENTION: Now here after running script and renaming, names of some files may coincide and there would be a conflict in this case. Can later fix it and update this script.

Related

Shell : Display a folder's files content (ls) , search for a file name and display it

I have a folder which may contain several files. Among those files I have files like these:
test.xml
test.jar
test.jarGENERATED
dev.project.jar
...
and many other files. To get only the "dev.project.jar" I have executed:
ls | grep ^{{dev}}.*.jar$
This displays the file with its properties for me. However, I only want the file name (only the file name string)
How to rectify it??
ls and grep are both unnecessary here. The shell will show you any file name matches for a wildcard:
echo dev.*.jar
(ls dev.*.jar without options will do something similar per se; if you see anything more than the filename, perhaps you have stupidly defined alias ls='ls -l' or something like that?)
The argument to grep should be a regular expression; what you specified would match {{dev}} and not dev, though in the absence of quoting, your shell might have expanded the braces. The proper regex would be grep '^dev\..*\.jar$' where the single quotes protect the regex from any shell expansions, and . matches any character, and * repeats that character as many times as possible. To match a literal dot, we backslash-escape it.
Just printing a file name is rarely very useful; often times, you actually want something like
for file in ./dev.*.jar; do
echo "$file"
: probably do more things with "$file"
done
though if that's all you want, maybe prefer printf over echo, which also lets you avoid the loop:
printf '%s\n' dev.*.jar

Mass renaming of files in folder

I need to renami all the files below few files format in the folder in such a way that last _2.txt will be the same and apac, emea, mds will be the same in all files but before _XXX_2.txt need to add logs_date to all the files.
ABC_xyz_123_apac_2.txt
POR5_emea_2.txt
qw_1_0_122_mds_2.txt
to
logs_date_apac_2.txt
logs_date_emea_2.txt
logs_date_mds_2.txt
I'm not sure but maybe this is what you want:
#!/bin/bash
for file in *_2.txt;do
# remove echo to rename the files once you check it does what you expect
echo mv -v "$file" "$(sed 's/.*\(_.*_2\.txt\)$/logs_date\1/' <<<"$file")"
done
Do you have to use bash?
Bulk Rename Utility is an awesome tool that can easily rename multiple files in an intuitive way.
http://www.bulkrenameutility.co.uk/Main_Intro.php
Using mmv command should be easy.
mmv '*_*_2.txt' 'logs_date_#2_2.txt' *.txt
You could also use the rename tool:
rename 's/.+(_[a-z]+_[0-9].)/logs_date$1/' files
This will give you the desired output.
If you don't want to or can't use sed, you can also try this, which might even run faster. No matter what solution you use, be sure to backup before if possible.
shopt +s extglob # turn on the extglob shell option, which enables several extended pattern matching operators
set +H # turn off ! style history substitution
for file in *_2.txt;do
# remove echo to rename the files once you check it does what you expect
echo mv -v "$file" "${file/?(*_)!(*apac*|*emea*|*mds*)_/logs_date_}"
done
${parameter/pattern/string} performs pattern substitution. First optionally a number of characters ending with an underscore are matched, then a following number of characters not containing apac, emea or mds and ending with an underscore are matched, then the match is replaced with "logs_date_".
Copied from the bash man page:
?(pattern-list)
Matches zero or one occurrence of the given patterns
*(pattern-list)
Matches zero or more occurrences of the given patterns
+(pattern-list)
Matches one or more occurrences of the given patterns
#(pattern-list)
Matches one of the given patterns
!(pattern-list)
Matches anything except one of the given patterns

how to address files by their suffix

I am trying to copy a .nii file (Gabor3.nii) path to a variable but even though the file is found by the find command, I can't copy the path to the variable.
find . -type f -name "*.nii"
Data= '/$PWD/"*.nii"'
output:
./Gabor3.nii
./hello.sh: line 21: /$PWD/"*.nii": No such file or directory
What went wrong
You show that you're using:
Data= '/$PWD/"*.nii"'
The space means that the Data= parts sets an environment variable $Data to an empty string, and then attempts to run '/$PWD/"*.nii"'. The single quotes mean that what is between them is not expanded, and you don't have a directory /$PWD (that's a directory name of $, P, W, D in the root directory), so the script "*.nii" isn't found in it, hence the error message.
Using arrays
OK; that's what's wrong. What's right?
You have a couple of options. The most reliable is to use an array assignment and shell expansion:
Data=( "$PWD"/*.nii )
The parentheses (note the absence of spaces before the ( — that's crucial) makes it an array assignment. Using shell globbing gives a list of names, preserving spaces etc in the names correctly. Using double quotes around "$PWD" ensures that the expansion is correct even if there are spaces in the current directory name.
You can find out how many files there are in the list with:
echo "${#Data[#]}"
You can iterate over the list of file names with:
for file in "${Data[#]}"
do
echo "File is [$file]"
ls -l "$file"
done
Note that variable references must be in double quotes for names with spaces to work correctly. The "${Data[#]}" notation has parallels with "$#", which also preserves spaces in the arguments to the command. There is a "${Data[*]}" variant which behaves analogously to "$*", and is of similarly limited value.
If you're worried that there might not be any files with the extension, then use shopt -s nullglob to expand the globbing expression into an empty list rather than the unexpanded expression which is the historical default. You can unset the option with shopt -u nullglob if necessary.
Alternatives
Alternatives involve things like using command substitution Data=$(ls "$PWD"/*.nii), but this is vastly inferior to using an array unless neither the path in $PWD nor the file names contain any spaces, tabs, newlines. If there is no white space in the names, it works OK; you can iterate over:
for file in $Data
do
echo "No white space [$file]"
ls -l "$file"
done
but this is altogether less satisfactory if there are (or might be) any white space characters around.
You can use command substitution:
Data=$(find . -type f -name "*.nii" -print -quit)
To prevent multiline output, the -quit option stop searching after the first file was found(unless you're sure only one file will be found or you want to process multiple files).
The syntax to do what you seem to be trying to do with:
Data= '/$PWD/"*.nii"'
would be:
Data="$(ls "$PWD"/*.nii)"
Not saying it's the best approach for whatever you want to do next of course, it's probably not...

Produce a file that contains names of all empty subfolders

I want to write a script that takes a name of a folder as a command line argument and produces a file that contains the names of all subfolders with size 0 (empty subfolder). This is what I got:
#!/bin/bash
echo "Name of a folder'
read FOLDER
for entry in "$search_dir"/*
do
echo "$entry"
done
your script doesn't have the logic you intended. find command has a feature for this
$ find path/to/dir -type d -empty
will print empty directories starting from the given path/to/dir
I would suggest you accept the answer which suggests to use find instead. But just to be complete, here is some feedback on your code.
You read the input directory into FOLDER but then never use this variable.
As an aside, don't use uppercase for your private variables; this is reserved for system variables.
You have unpaired quotes in the prompt string. If the opening quote is double, you need to close with a double quote, or vice versa for single quotes.
You loop over directory entries, but do nothing to isolate just the ones which are directories, let alone empty directories.
Finally, nothing in your script uses Bash-only facilities, so it would be safe and somewhat more portable to use #!/bin/sh
Now, looping over directories can be done by using search_dir/*/ instead of just search_dir/*; and finding out which ones are empty can be done by checking whether a wildcard within the directory returns just the directory itself. (This assumes default globbing behavior -- with nullglob you would make a wildcard with no matches expand to an empty list, but this is problematic in some scenarios so it's not the default.)
#!/bin/bash
# read -p is not POSIX
read -p "Name of a folder" search_dir
for dir in "$search_dir"/*/
do
# [[ is Bash only
if [[ "$dir"/* = "$dir/*" ]]; then # Notice tricky quoting
echo "$dir"
fi
done
Using the wildcard expansion with [ is problematic because it is not prepared to deal with a wildcard expansion -- you get "too many arguments" if the wildcard expands into more than one filename -- so I'm using the somewhat more mild-tempered Bash replacement [[ which copes just fine with this. Alternatively, you could use case, which I would actually prefer here; but I've stuck to if in order to make only minimal changes to your script.

bash - mass renaming files with many special characters

I have a lot of files (in single directory) like:
[a]File-. abc'.d -001[xxx].txt
so there are many spaces, apostrophes, brackets, and full stops. The only differences between them are numbers in place of 001, and letters in place of xxx.
How to remove the middle part, so all that remains would be
[a]File-001[xxx].txt
I'd like an explanation how such code would work, so I could adapt it for other uses, and hopefully help answer others similar questions.
Here is a simple script in pure bash:
for f in *; do # for all entries in the current directory
if [ -f "$f" ]; then # if the entry is a regular file (i.e. not a directory)
mv "$f" "${f/-*-/-}" # rename it by removing everything between two dashes
# and the dashes, and replace the removed part
# with a single dash
fi
done
The magic done in the "${f/-*-/-}" expression is described in the bash manual (the command is info bash) in the chapter 3.5.3 Shell Parameter Expansion
The * pattern in the first line of the script can be replaced with anything than can help to narrow the list of the filles you want to rename, e.g. *.txt, *File*.txt, etc.
If you have the rename (aka prename) utility that's a part of Perl distribution, you could say:
rename -n 's/([^-]*-).*-(.*)/$1$2/' *.txt
to rename all txt files in your desired format. The -n above would not perform the actual rename, it'd only tell you what it would do had you not specified it. (In order to perform the actual rename, remove -n from the above command.)
For example, this would rename the file
[a]File-. abc'.d -001[xxx].txt
as
[a]File-001[xxx].txt
Regarding the explanation, this captures the part upto the first - into a group, and the part after the second (or last) one into another and combines those.
Read about Regular Expressions. If you have perl docs available on your system, saying perldoc perlre should help.

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