Export and pipe

Export the filtered entries of your last tail to a file, or pipe them to another command.

Export to a file

Basic export

pgtail> export /tmp/errors.log
Exported 42 entries to /tmp/errors.log

Exports the entries of the last tail that match the current filters. If the file exists, pgtail asks before replacing it: File /tmp/errors.log exists. Overwrite? [y/N].

Formats

export --format text /tmp/logs.txt    # The log lines as PostgreSQL wrote them (default)
export --format json /tmp/logs.json   # JSON Lines
export --format csv /tmp/logs.csv     # CSV with a header row

JSON Lines writes one object per entry, and CSV one row per entry with the same fields:

{"timestamp": "2024-01-15T10:30:45.123000+00:00", "level": "ERROR", "pid": 12345, "message": "relation \"users\" does not exist"}

timestamp,level,pid,message

Keeping colors

export --highlighted /tmp/colored.log

Writes each text entry as pgtail displays it, with its colors as ANSI escape sequences, for viewing with less -R or cat.

Append mode

export --append /tmp/logs.txt

Adds to the end of an existing file instead of replacing it.

Time-scoped export

export --since 1h /tmp/recent.log

Exports only entries from the last hour. --since takes any time format.

Continuous export

export --follow /tmp/live.log

Keeps writing new entries to the file as they arrive, like tail -f | tee, and shows them on screen as well. Press Ctrl+C to stop. --follow cannot be combined with --append or --since.

Pipe to commands

Basic pipe

pgtail> pipe wc -l

Sends the filtered entries to a command’s standard input and prints what it writes. The command runs in your shell (sh -c, or cmd /c on Windows), so pipes and quoting work as they would at a prompt.

With a format

pipe --format json jq -r '.level'

Examples

pipe grep ERROR                                   # Search within entries
pipe wc -l                                        # Count entries
pipe sort | uniq -c                               # Count identical lines
pipe --format json jq -r '.level' | sort | uniq -c   # Count entries by level

The command’s error output is printed after stderr:, and a non-zero exit code is reported.

Export in tail mode

Tail mode has its own export, which writes the entries the log is showing:

tail> export /tmp/logs.txt
tail> export /tmp/logs.json --format json
tail> export /tmp/logs.txt --highlighted

The entry buffer

export and pipe in the REPL work on the entries of the most recent tail:

• The last 10,000 entries are kept
• Filters apply when you export, so you can change them and export again
• Both full screen tail mode and streaming fill the buffer, and it stays after you leave tail mode

pgtail> tail 0
# ... read the log, leave with 'q' ...
pgtail> export /tmp/session.log

If nothing has been tailed yet, export and pipe say No log file loaded. Use 'tail <instance>' first.