IFS=$'?\n'
for line in $(cat "./newfiletoread")
do printf "${line}\n"
done
The file contents are as below: Hello there!How are you doing?How is life?Mine is as boring as a winter morning!
The code above splits the contents of the file when it comes across a '?' or '!' or '/n' which is nice. But, during the expansion the shell removes these characters from the file. The below is the output that I get.
Hello there
How are you doing
How is life
Mine is as boring as a winter morning
I understand that it is how shell works by substituting these IFS values with spaces before the command executes. Is there a way to preserve these delimiter characters during the splitting? I would like to get my output like this one below:
Hello there!
How are you doing?
How is life?
Mine is as boring as a winter morning!
First, don't read the lines of a file with for
I read this somewhere about splitting strings: use split when you know what to throw away; use a regular expression when you know what you want to keep. Or something like that.
The problem with using shell word splitting using $IFS is that any char in that variable is used to split, and you can't know which one.
With bash, you can write:
line='Hello there! How are you doing? How is life? Mine is as boring as a winter morning!'
line=${line//\?/$'"?\n'}
line=${line//\!/$'"!\n'}
echo "$line"
Hello there"!
How are you doing"?
How is life"?
Mine is as boring as a winter morning"!
Note the leading spaces. That can be worked around with a more complicated pattern: line=${line//\?*([[:blank:]])/$'"?\n'}
I would use sed instead:
line='Hello there! How are you doing? How is life? Mine is as boring as a winter morning!'
new=$( sed 's/[?!][[:blank:]]*/&\n/g' <<<"$line" )
echo "$new"
Hello there!
How are you doing?
How is life?
Mine is as boring as a winter morning!
awk has a split() function that does let you capture the separators, but using it is pretty verbose:
echo "$line" | awk '{
n = split($0, words, /[!?][[:blank:]]*/, seps)
for (i = 1; i < n; i++)
print words[i] seps[i]
print words[n]}
'
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