extract part of a string using bash/cut/split

Question

I have a string like this:

/var/cpanel/users/joebloggs:DNS9=domain.com

I need to extract the username (joebloggs) from this string and store it in a variable.

The format of the string will always be the same with exception of joebloggs and domain.com so I am thinking the string can be split twice using cut?

The first split would split by : and we would store the first part in a variable to pass to the second split function.

The second split would split by / and store the last word (joebloggs) into a variable

I know how to do this in php using arrays and splits but I am a bit lost in bash.

Answer 1

To extract joebloggs from this string in bash using parameter expansion without any extra processes...

MYVAR="/var/cpanel/users/joebloggs:DNS9=domain.com" 

NAME=${MYVAR%:*}  # retain the part before the colon
NAME=${NAME##*/}  # retain the part after the last slash
echo $NAME

Doesn't depend on joebloggs being at a particular depth in the path.

---

Summary

An overview of a few parameter expansion modes, for reference...

${MYVAR#pattern}     # delete shortest match of pattern from the beginning
${MYVAR##pattern}    # delete longest match of pattern from the beginning
${MYVAR%pattern}     # delete shortest match of pattern from the end
${MYVAR%%pattern}    # delete longest match of pattern from the end

So # means match from the beginning (think of a comment line) and % means from the end. One instance means shortest and two instances means longest.

You can get substrings based on position using numbers:

${MYVAR:3}   # Remove the first three chars (leaving 4..end)
${MYVAR::3}  # Return the first three characters
${MYVAR:3:5} # The next five characters after removing the first 3 (chars 4-9)

You can also replace particular strings or patterns using:

${MYVAR/search/replace}

The pattern is in the same format as file-name matching, so * (any characters) is common, often followed by a particular symbol like / or .

Examples:

Given a variable like

MYVAR="users/joebloggs/domain.com" 

Remove the path leaving file name (all characters up to a slash):

echo ${MYVAR##*/}
domain.com

Remove the file name, leaving the path (delete shortest match after last /):

echo ${MYVAR%/*}
users/joebloggs

Get just the file extension (remove all before last period):

echo ${MYVAR##*.}
com

NOTE: To do two operations, you can't combine them, but have to assign to an intermediate variable. So to get the file name without path or extension:

NAME=${MYVAR##*/}      # remove part before last slash
echo ${NAME%.*}        # from the new var remove the part after the last period
domain