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Monitor a file with tail with timestamps added

Terminal - Monitor a file with tail with timestamps added
tail -f file |xargs -IX printf "$(date -u)\t%s\n" X
2010-11-25 11:23:13
User: unefunge
Functions: file printf tail xargs
2
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Monitor a file with tail with timestamps added
Add to favourites | Report as malicious

Alternatives

There are 2 alternatives - vote for the best!

Terminal - Alternatives
tail -f file | awk '{now=strftime("%F %T%z\t");sub(/^/, now);print}'
2010-11-25 04:11:52
User: arcege
Functions: awk file tail
Tags: awk tail
7
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Down
Monitor a file with tail with timestamps added
Comments (2) | Add to favourites | Report as malicious
tail -f file | while read line; do echo -n $(date -u -Ins); echo -e "\t$line"; done
2010-11-19 10:01:57
User: hfs
Functions: date echo file read tail
Tags: tail date
5
Up
Down
Monitor a file with tail with timestamps added

This is useful when watching a log file that does not contain timestamps itself.

If the file already has content when starting the command, the first lines will have the "wrong" timestamp when the command was started and not when the lines were originally written.

Comments (4) | Add to favourites | Report as malicious
tail -f file | while read line; do printf "$(date -u '+%F %T%z')\t$line\n"; done
2010-11-24 05:50:12
User: derekschrock
Functions: file printf read tail
Tags: tail date
3
Up
Down
Monitor a file with tail with timestamps added

Should be a bit more portable since echo -e/n and date's -Ins are not.

Show sample output | Comments (0) | Add to favourites | Report as malicious

Know a better way?

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What others think

This always prints the same timestamp on each line.

Comment by yoyoyojomo 112 weeks and 6 days ago

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