How to use IFS with multiple delimiters?

user_16196264 0
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Data in the log file goes like this

username - yyyy-mm-dd, HH:MM:SS

Now how to seperate username, date and time?

I tried using.

while IFS=" - |, " read G1 G2 G3

But this considers the hyphen between the date.. any idea?

EDIT: I actually found a method .....

I used

while IFS="-""," read G1 G2 G3 G4

And G1 was the username , G2 was - G3 was date and G4 was the time..

I couldn't understand how this works.. but it worked

Thanks

terminal linux bash
3 Answers

You may try this script in bash:

while IFS= read -r && read G1 G2 G3 <<< "${REPLY//[,-]/}"; do
   echo "[$G1][$G2][$G3]"
done < file.log

Output:

[username][yyyymmdd][HH:MM:SS]

Here we are reading full line in internal REPLY variable first then we use another read to get values in 3 variables after cleaning up $REPLY by removing - and , upfront.

user_5482250

How to use IFS with multiple delimiters?

It is possible to use IFS with multiple single character delimiters. Any character in the set in IFS is considered a delimiter. The IFS=" - |, " is equal to IFS=" -|," - repeated characters are ignored.

It's not possible to use IFS splitting with any multi-character delimiters.

any idea?

Use another tool and do the splitting yourself. You could match the line with regex with bash [[ =~ matching or in sed or use awk to parse the line or use other tools.

user_90727530

Another approach is to use a dummy variable to hold the dash - and do a Parameter Expansion to remove the trailing comma , e.g. "${date%,}"

while read -r username _ date time; do
   echo "$username" "${date%,}" "$time"
done < log.txt
user_44522650
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