Shell Programming and Scripting

I have command like below.
[ls /a/bc_de/fe_rt/ghl/CW_CA_CA_20140128_150752.xml]

From the above command, how I can cut and take time field 20140128_150752 alone

---------- Post updated at 01:45 AM ---------- Previous update was at 01:44 AM ----------

Code:

 
ls /a/bc_de/fe_rt/ghl/CW_CA_CA_20140128_150752.xml

A few questions first:-Most importantly, What have you tried so far?

You will get a better answer if you can show that you've put some effort in.




Robin

Code:

echo "/a/bc_de/fe_rt/ghl/CW_CA_CA_20140128_150752.xml" | cut -d / -d _ -f 6,7 | cut -d . -f 1

Not exactly certain on what you mean, I agree with techmonk to use cut if you certain with the format is always the same.

Another way using sed, depends on what is your exact requirement.

Code:

$ ls a/bc_de/fe_rt/ghl/CW_CA_CA_20140128_150752.xml | xargs basename | sed -n 's/.*_\([0-9]*_[0-9]*\).xml/\1/p'
20140128_150752

Invoking cut twice or ls, xargs, and basename are very expensive ways to do this.

Making a several assumptions about what is wanted here (and only using shell built-ins):

Code:

#!/bin/ksh
path="/a/bc_de/fe_rt/ghl/CW_CA_CA_20140128_150752.xml"

if [ ! -e "$path" ]
then	printf "ls: %s: No such file or directory\n" "$path" >&2
	exit 1
fi
out=${path##*[![:digit:]]_}
out=${out%.*}
printf "%s\n" "$out"

produces the output:

Code:

20140128_150752

if the file exists, and writes the diagnostic:

Code:

ls: /a/bc_de/fe_rt/ghl/CW_CA_CA_20140128_150752.xml: No such file or directory

to standard error output and exits with a non-zero exit status if it doesn't exist.

Of course, however, this doesn't give you the localized diagnostics you should get from ls if you're using a non-English locale.

Although this was tested using the Korn shell, this will work with any shell that performs the parameter expansions required by the POSIX standards (such as ksh and bash).