How can I remove all text after a character in bash?
BashBash Problem Overview
How can I remove all text after a character, in this case a colon (":"), in bash? Can I remove the colon, too? I have no idea how to.
Bash Solutions
Solution 1 - Bash
In Bash (and ksh, zsh, dash, etc.), you can use parameter expansion with % which will remove characters from the end of the string or # which will remove characters from the beginning of the string. If you use a single one of those characters, the smallest matching string will be removed. If you double the character, the longest will be removed.
$ a='hello:world'
$ b=${a%:*}
$ echo "$b"
hello
$ a='hello:world:of:tomorrow'
$ echo "${a%:*}"
hello:world:of
$ echo "${a%%:*}"
hello
$ echo "${a#*:}"
world:of:tomorrow
$ echo "${a##*:}"
tomorrow
Solution 2 - Bash
An example might have been useful, but if I understood you correctly, this would work:
echo "Hello: world" | cut -f1 -d":"
This will convert Hello: world into Hello.
Solution 3 - Bash
$ echo 'hello:world:again' |sed 's/:.*//'
hello
Solution 4 - Bash
egrep -o '^[^:]*:'
Solution 5 - Bash
I know some solutions:
# Our mock data:
A=user:mail:password
- With awk and pipe:
$ echo $A | awk -v FS=':' '{print $1}'
user
- Via bash variables:
$ echo ${A%%:*}
user
- With pipe and sed:
$ echo $A | sed 's#:.*##g'
user
- With pipe and grep:
$ echo $A | egrep -o '^[^:]+'
user
- With pipe and cut:
$ echo $A | cut -f1 -d\:
user
Solution 6 - Bash
Let's say you have a path with a file in this format:
/dirA/dirB/dirC/filename.file
Now you only want the path which includes four "/". Type
$ echo "/dirA/dirB/dirC/filename.file" | cut -f1-4 -d"/"
and your output will be
/dirA/dirB/dirC
The advantage of using cut is that you can also cut out the uppest directory as well as the file (in this example), so if you type
$ echo "/dirA/dirB/dirC/filename.file" | cut -f1-3 -d"/"
your output would be
/dirA/dirB
Though you can do the same from the other side of the string, it would not make that much sense in this case as typing
$ echo "/dirA/dirB/dirC/filename.file" | cut -f2-4 -d"/"
results in
dirA/dirB/dirC
In some other cases the last case might also be helpful. Mind that there is no "/" at the beginning of the last output.
Solution 7 - Bash
trim off everything after the last instance of ":"
grep -o '^.*:' fileListingPathsAndFiles.txt
and if you wanted to drop that last ":"
grep -o '^.*:' file.txt | sed 's/:$//'
@kp123: you'd want to replace : with / (where the sed colon should be \/)