CODEWITHSUNDEEP
bashpg-dump
Tim Duncklee
Tim Duncklee

Reputation: 1420

How can I capture STDERR into bash variable and not affect STDOUT?

I'm trying to capture the error from pg_dump and cannot figure out how to get it into a bash variable. This does not work because STDOUT is going to gzip.

OUTPUT=$(/bin/pg_dump -c --if-exists --dbname=cfMaster -U cfMaster | /bin/gzip > ~cftvdun/dbbackups/cfMaster.tmp.sql.gz)

How can I get STDERR into a bash variable in this situation?

Upvotes: 1

Views: 200

Answers (1)

Gordon Davisson
Gordon Davisson

Reputation: 125788

The $( ) construct always captures stdout, but you can juggle between file descriptors. Just group the pipeline in { }, and then redirect the stderr of the group to standard output with 2>&1:

output=$( { /bin/pg_dump -c --if-exists --dbname=cfMaster -U cfMaster | /bin/gzip > ~cftvdun/dbbackups/cfMaster.tmp.sql.gz; } 2>&1 )

If you also wanted the standard output (rather than just sending it to a file), it'd get more complicated. I think in that case you'd have to juggle through FD #3.

BTW, I'd also recommend using lowercase (or mixed-case) variable names to avoid accidental conflicts with the variables with special meaning to the shell or other utilities.

Upvotes: 2

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