The sed command below enables me to convert all the commas into the string and:

markers=$(echo generic,daily,nightly | sed -e "s/,/ and /g")

echo $markers will result in:

generic and daily and nightly

Now I would like to achieve the following:

If the word nightly is not present in the $markers it should add the string and not nightly to $markers string

Is that possible to achieve it with sed?

CodePudding user response：

You can use

#!/bin/bash

s='generic,daily,weekly,monthly
generic,daily,nightly,weekly,monthly'
markers=$(echo "$s" | sed -e "s/,/ and /g" -e "/nightly/!s/$/ and not nightly/")
echo "$markers"

Output:

generic and daily and weekly and monthly and not nightly
generic and daily and nightly and weekly and monthly

See the online demo. The /nightly/!s/$/ and not nightly/ does the following:

• /nightly/! - skip a line if it contains nightly, else
• s/$/ and not nightly/ - replace end of string with and not nightly.