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Archive of posts filed under the tips category.

“In-place” editing of files

Temporary files don't bite, so just use them.

DNSSEC verification with dig

Perform DNSSEC verification from the command line.

Awk pitfall: string concatenation

This is a bit of a dark corner of awk. This beast is string concatenation. There is a classical example in the awk FAQ number 28: $ awk 'BEGIN { print 6 " " -22 }' 6-22 Where did the space go? First, " " -22 is evaluated, in numeric context, yielding 0-22 = -22. [...]

On pipes, subshells and descriptors

When small differences in implementation bite you.

Smart ranges in awk, part two

Another variation on the theme