I am trying to replace the prefix of all files in the directory with another prefix (renaming).
This is my script
# Script to rename the files
#!/bin/bash
for file in $1*;
do
mv $file `echo $file | sed -e 's/^$1/$2/'`;
done
Upon executing the script with
rename.sh BIT SIT
I get the following errors
mv: `BITfile.h' and `BITFile.h' are the same file
mv: `BITDefs.cpp' and `BITDefs.cpp' are the same file
mv: `BITDefs.h' and `BITDefs.h' are the same file
Seems like sed is treating $1 and $2 as the same value, but when I print those variables on another line it shows that they are different.
As Roman Newaza says, you can use " instead of ' to tell Bash that you want variables to be expanded. However, in your case, it would be safest to write:
for file in "$1"* ; do
mv -- "$file" "$2${file#$1}"
done
so that weird characters in filenames, or in your script parameters, cannot cause any problems.
You can also use parameter expansion to replace the prefix of all files in a directory.
for file in "$1"*;
do
mv ${file} ${file/#$1/$2}
done
Use double quotes instead:
# ...
mv "$file" `echo $file | sed -e "s/^$1/$2/"`
# ...
And learn Quotes and escaping in Bash.
When you don't use double quotes, the variables won't expand.
I will rather use this
#!/bin/bash
for file in $1*;
do
mv "$file" "$1${file:${#2}}"
done
where
${file:${#2}
means substring, from length of the argument 2 to the end
Related
I am currently trying to list the size of all files in a directory which is passed as the first argument to the script, but the -f option in Linux is not working, or am I missing something.
Here is the code :
for tmp in "$1/*"
do
echo $tmp
if [ -f "$tmp" ]
then num=`ls -l $tmp | cut -d " " -f5`
echo $num
fi
done
How would I fix this problem?
I think the error is with your glob syntax which doesn't work in either single- or double-quotes,
for tmp in "$1"/*; do
..
Do the above to expand the glob outside the quotes.
There are couple more improvements possible in your script,
Double-quote your variables to prevent from word-splitting, e.g. echo "$temp"
Backtick command substitution `` is legacy syntax with several issues, use the $(..) syntax.
The [-f "filename"] condition check in linux is for checking the existence of a file and it is a regular file. For reference, use this text as reference,
-b FILE
FILE exists and is block special
-c FILE
FILE exists and is character special
-d FILE
FILE exists and is a directory
-e FILE
FILE exists
-f FILE
FILE exists and is a regular file
-g FILE
FILE exists and is set-group-ID
-G FILE
FILE exists and is owned by the effective group ID
I suggest you try with [-e "filename"] and see if it works.
Cheers!
At least on the command line, this piece of script does it:
for tmp in *; do echo $tmp; if [ -f $tmp ]; then num=$(ls -l $tmp | sed -e 's/ */ /g' | cut -d ' ' -f5); echo $num; fi; done;
If cut uses space as delimiter, it cuts at every space sign. Sometimes you have more than one space between columns and the count can easily go wrong. I'm guessing that in your case you just happened to echo a space, which looks like nothing. With the sed command I remove extra spaces.
When creating playlists I often came across files that would break the playing process. Such would be files with spaces or apostrophes. I would fix it with the following command
for file in *.; do mv "$file" `echo $file | tr " " '_'` ; done **(for spaces)**
Now I more often come across files with commas, apostrophes, brackets and other characters. How would I modify the command to remove such characters?
Also tried rename 's/[^a-zA-Z0-9_-]//' *.mp4 but it doesnt seem to remove spaces or commas
for file in *; do mv "$file" $(echo "$file" | sed -e 's/[^A-Za-z0-9._-]/_/g'); done &
Your rename would work if you add the g modifier to it, this performs all substitutions instead of only the first one:
$ echo "$file"
foo bar,spam.egg
$ rename -n 's/[^a-zA-Z0-9_-]//' "$file"
foo bar,spam.egg renamed as foobar,spam.egg
$ rename -n 's/[^a-zA-Z0-9_-]//g' "$file"
foo bar,spam.egg renamed as foobarspamegg
You can do this will bash alone, with parameter expansion:
For removing everything except a-zA-Z0-9_- from file names, assuming variable file contains the filename, using character class [:alnum:] to match all alphabetic characters and digits from current locale:
"${file//[^[:alnum:]_-]/}"
or explicitly, change the LC_COLLATE to C:
"${file//[^a-zA-Z0-9_-]/}"
Example:
$ file='foo bar,spam.egg'
$ echo "${file//[^[:alnum:]_-]/}"
foobarspamegg
I'm trying to concatenate a bunch of files into a string so I can use them for a function.
As a test script I'm trying to do this:
#!/bin/bash
for line in $(cat list.txt)
do
x=" "
A=$A$line$x
done
echo "$A"
mv "$A" ./stuff
but I'm getting the error:
mv: cannot stat ‘x.dat y.dat z.dat ’: No such file or directory
but they are most definitely there
can I get some advice please?
This solution will handle file names with spaces too.
#!/bin/bash
mapfile -t lines < list.txt
echo "${lines[#]}"
mv "${lines[#]}" ./stuff/
It reads the entire contents of the file into an array variable, displays the content of the entire array, and finally uses those values in the mv command
Change the last line to mv $A ./stuff
That should work with files that do not have space in their names.
I want to add the string %%% to the beginning of some specific lines in a text file.
This is my script:
#!/bin/bash
a="c:\Temp"
sed "s/$a/%%%$a/g" <File.txt
And this is my File.txt content:
d:\Temp
c:\Temp
e:\Temp
But nothing changes when I execute it.
I think the 'sed' command is not finding the pattern, possibly due to the \ backslashes in the variable a.
I can find the c:\Temp line if I use grep with -F option (to not interpret strings):
cat File.txt | grep -F "$a"
But sed seems not to implement such '-F` option.
Not working neither:
sed 's/$a/%%%$a/g' <File.txt
sed 's/"$a"/%%%"$a"/g' <File.txt
I have found similar threads about replacing with sed, but they don't refer to variables.
How can I replace the desired lines by using a variable adding them the %%% char string?
EDIT: It would be fine that the $a variable could be entered via parameter when calling the script, so it will be assigned like:
a=$1
Try it like this:
#!/bin/sh
a='c:\\Temp' # single quotes
sed "s/$a/%%%$a/g" <File.txt # double quotes
Output:
Johns-MacBook-Pro:sed jcreasey$ sh x.sh
d:\Temp
e:\Temp
%%%c:\Temp
You need the double slash '\' to escape the '\'.
The single quotes won't expand the variables.
So you escape the slash in single quotes and pass it into the double quotes.
Of course you could also just do this:
#!/bin/sh
sed 's/\(.*Temp\)/%%%&/' <File.txt
If you want to get input from the command line you have to allow for the fact that \ is an escape character there too. So the user needs to type 'c:\\' or the interpreter will just wait for another character. Then once you get it, you will need to escape it again. (printf %q).
#!/bin/sh
b=`printf "%q" $1`
sed "s/\($b\)/%%% &/" < File.txt
The issue you are having has to do with substitution of your variable providing a regular expression looking for a literal c:Temp with the \ interpreted as an escape by the shell. There are a number of workarounds. Seeing the comments and having worked through the possibilities, the following will allow the unquoted entry of the search term:
#!/bin/bash
## validate that needed input is given on the command line
[ -n "$1" -a "$2" ] || {
printf "Error: insufficient input. Usage: %s <term> <file>\n" "${0//*\//}" >&2
exit 1
}
## validate that the filename given is readable
[ -r "$2" ] || {
printf "Error: file not readable '%s'\n" "$2" >&2
exit 1
}
a="$1" # assign a
filenm="$2" # assign filename
## test and fix the search term entered
[[ "$a" =~ '/' ]] || a="${a/:/:\\}" # test if \ removed by shell, if so replace
a="${a/\\/\\\\}" # add second \
sed -e "s/$a/%%%$a/g" "$filenm" # call sed with output to stdout
Usage:
$ bash sedwinpath.sh c:\Temp dat/winpath.txt
d:\Temp
%%%c:\Temp
e:\Temp
Note: This allows both single-quoted or unquoted entry of the dos path search term. To edit in place use sed -i. Additionally, the [[ operator and =~ operator are limited to bash.
I could have sworn the original question said replace, but to append, just as you suggest in the comments. I have updated the code with:
sed -e "s/$a/%%%$a/g" "$filenm"
Which provides the new output:
$ bash sedwinpath.sh c:\Temp dat/winpath.txt
d:\Temp
%%%c:\Temp
e:\Temp
Remember: If you want to edit the file in place use sed -i or sed -i.bak which will edit the actual file (and if -i.bak is given create a backup of the original in originalname.bak). Let me know if that is not what you intended and I'm happy to edit again.
Creating your script with a positional parameter of $1
#!/bin/bash
a="$1"
cat <file path>|sed "s/"$1"/%%%"$1"/g" > "temporary file"
Now whenever you want sed to find "c:\Temp" you need to use your script command line as follows
bash <my executing script> c:\\\\Temp
The first backslash will make bash interpret any backslashes that follows therefore what will be save in variable "a" in your executing script is "c:\\Temp". Now substituting this variable in sed will cause sed to interpret 1 backlash since the first backslash in this variable will cause sed to start interpreting the other backlash.
when you Open your temporary file you will see:
d:\Temp
%%%c:\Temp
e:\Temp
I have a folder that is full of .bak files and some other files also. I need to remove the extension of all .bak files in that folder. How do I make a command which will accept a folder name and then remove the extension of all .bak files in that folder ?
Thanks.
To remove a string from the end of a BASH variable, use the ${var%ending} syntax. It's one of a number of string manipulations available to you in BASH.
Use it like this:
# Run in the same directory as the files
for FILENAME in *.bak; do mv "$FILENAME" "${FILENAME%.bak}"; done
That works nicely as a one-liner, but you could also wrap it as a script to work in an arbitrary directory:
# If we're passed a parameter, cd into that directory. Otherwise, do nothing.
if [ -n "$1" ]; then
cd "$1"
fi
for FILENAME in *.bak; do mv "$FILENAME" "${FILENAME%.bak}"; done
Note that while quoting your variables is almost always a good practice, the for FILENAME in *.bak is still dangerous if any of your filenames might contain spaces. Read David W.'s answer for a more-robust solution, and this document for alternative solutions.
There are several ways to remove file suffixes:
In BASH and Kornshell, you can use the environment variable filtering. Search for ${parameter%word} in the BASH manpage for complete information. Basically, # is a left filter and % is a right filter. You can remember this because # is to the left of %.
If you use a double filter (i.e. ## or %%, you are trying to filter on the biggest match. If you have a single filter (i.e. # or %, you are trying to filter on the smallest match.
What matches is filtered out and you get the rest of the string:
file="this/is/my/file/name.txt"
echo ${file#*/} #Matches is "this/` and will print out "is/my/file/name.txt"
echo ${file##*/} #Matches "this/is/my/file/" and will print out "name.txt"
echo ${file%/*} #Matches "/name.txt" and will print out "/this/is/my/file"
echo ${file%%/*} #Matches "/is/my/file/name.txt" and will print out "this"
Notice this is a glob match and not a regular expression match!. If you want to remove a file suffix:
file_sans_ext=${file%.*}
The .* will match on the period and all characters after it. Since it is a single %, it will match on the smallest glob on the right side of the string. If the filter can't match anything, it the same as your original string.
You can verify a file suffix with something like this:
if [ "${file}" != "${file%.bak}" ]
then
echo "$file is a type '.bak' file"
else
echo "$file is not a type '.bak' file"
fi
Or you could do this:
file_suffix=$(file##*.}
echo "My file is a file '.$file_suffix'"
Note that this will remove the period of the file extension.
Next, we will loop:
find . -name "*.bak" -print0 | while read -d $'\0' file
do
echo "mv '$file' '${file%.bak}'"
done | tee find.out
The find command finds the files you specify. The -print0 separates out the names of the files with a NUL symbol -- which is one of the few characters not allowed in a file name. The -d $\0means that your input separators are NUL symbols. See how nicely thefind -print0andread -d $'\0'` together?
You should almost never use the for file in $(*.bak) method. This will fail if the files have any white space in the name.
Notice that this command doesn't actually move any files. Instead, it produces a find.out file with a list of all the file renames. You should always do something like this when you do commands that operate on massive amounts of files just to be sure everything is fine.
Once you've determined that all the commands in find.out are correct, you can run it like a shell script:
$ bash find.out
rename .bak '' *.bak
(rename is in the util-linux package)
Caveat: there is no error checking:
#!/bin/bash
cd "$1"
for i in *.bak ; do mv -f "$i" "${i%%.bak}" ; done
You can always use the find command to get all the subdirectories
for FILENAME in `find . -name "*.bak"`; do mv --force "$FILENAME" "${FILENAME%.bak}"; done