Get just the filename from a path in a Bash script

How would I get just the filename without the extension and no path?

The following gives me no extension, but I still have the path attached:

source_file_filename_no_ext=${source_file%.*}

Many UNIX-like operating systems have a basename executable for a very similar purpose (and dirname for the path):

pax> full_name=/tmp/file.txt
pax> base_name=$(basename ${full_name})
pax> echo ${base_name}
file.txt

That unfortunately just gives you the file name, including the extension, so you'd need to find a way to strip that off as well.

So, given you have to do that anyway, you may as well find a method that can strip off the path and the extension.

One way to do that (and this is a bash-only solution, needing no other executables):

pax> full_name=/tmp/xx/file.tar.gz
pax> xpath=${full_name%/*} 
pax> xbase=${full_name##*/}
pax> xfext=${xbase##*.}
pax> xpref=${xbase%.*}
pax> echo "path='${xpath}', pref='${xpref}', ext='${xfext}'"

path='/tmp/xx', pref='file.tar', ext='gz'

That little snippet sets xpath (the file path), xpref (the file prefix, what you were specifically asking for) and xfext (the file extension).

basename and dirname solutions are more convenient. Those are alternative commands:

FILE_PATH="/opt/datastores/sda2/test.old.img"
echo "$FILE_PATH" | sed "s/.*\///"

This returns test.old.img like basename.

This is salt filename without extension:

echo "$FILE_PATH" | sed -r "s/.+\/(.+)\..+/\1/"

It returns test.old.

And following statement gives the full path like dirname command.

echo "$FILE_PATH" | sed -r "s/(.+)\/.+/\1/"

It returns /opt/datastores/sda2

Here is an easy way to get the file name from a path:

echo "$PATH" | rev | cut -d"/" -f1 | rev

To remove the extension you can use, assuming the file name has only ONE dot (the extension dot):

cut -d"." -f1

$ file=${$(basename $file_path)%.*}

Some more alternative options because regexes (regi ?) are awesome!

Here is a Simple regex to do the job:

 regex="[^/]*$"

Example (grep):

 FP="/hello/world/my/file/path/hello_my_filename.log"
 echo $FP | grep -oP "$regex"
 #Or using standard input
 grep -oP "$regex" <<< $FP

Example (awk):

 echo $FP | awk '{match($1, "$regex",a)}END{print a[0]}
 #Or using stardard input
 awk '{match($1, "$regex",a)}END{print a[0]} <<< $FP

If you need a more complicated regex: For example your path is wrapped in a string.

 StrFP="my string is awesome file: /hello/world/my/file/path/hello_my_filename.log sweet path bro."
 
 #this regex matches a string not containing / and ends with a period 
 #then at least one word character 
 #so its useful if you have an extension
 
 regex="[^/]*\.\w{1,}"

 #usage
 grep -oP "$regex" <<< $StrFP
 
 #alternatively you can get a little more complicated and use lookarounds
 #this regex matches a part of a string that starts with /  that does not contain a / 
 ##then uses the lazy operator ? to match any character at any amount (as little as possible hence the lazy)
 ##that is followed by a space
 ##this allows use to match just a file name in a string with a file path if it has an exntension or not
 ##also if the path doesnt have file it will match the last directory in the file path 
 ##however this will break if the file path has a space in it.
 
 regex="(?<=/)[^/]*?(?=\s)"

 #to fix the above problem you can use sed to remove spaces from the file path only
 ## as a side note unfortunately sed has limited regex capibility and it must be written out in long hand.
 NewStrFP=$(echo $StrFP | sed 's:\(/[a-z]*\)\( \)\([a-z]*/\):\1\3:g')
 grep -oP "$regex" <<< $NewStrFP

Total solution with Regexes:

This function can give you the filename with or without extension of a linux filepath even if the filename has multiple "."s in it. It can also handle spaces in the filepath and if the file path is embedded or wrapped in a string.

#you may notice that the sed replace has gotten really crazy looking
#I just added all of the allowed characters in a linux file path
function Get-FileName(){
	local FileString="$1"
    local NoExtension="$2"
	local FileString=$(echo $FileString | sed 's:\(/[a-zA-Z0-9\<\>\|\\\:\)\(\&\;\,\?\*]*\)\( \)\([a-zA-Z0-9\<\>\|\\\:\)\(\&\;\,\?\*]*/\):\1\3:g')

	local regex="(?<=/)[^/]*?(?=\s)"
    
	local FileName=$(echo $FileString | grep -oP "$regex")

    if [[ "$NoExtension" != "" ]]; then
        sed 's:\.[^\.]*$::g' <<< $FileName
    else
        echo "$FileName"
    fi
}

## call the function with extension
Get-FileName "my string is awesome file: /hel lo/world/my/file test/path/hello_my_filename.log sweet path bro."

##call function without extension
Get-FileName "my string is awesome file: /hel lo/world/my/file test/path/hello_my_filename.log sweet path bro." "1"

If you have to mess with a windows path you can start with this one:

 [^\\]*$       

$ source_file_filename_no_ext=${source_file%.*}
$ echo ${source_file_filename_no_ext##*/}