helpTextVerbose
auto helpTextVerbose =
q"EOS
Synopsis: tsv-join --filter-file file [options] file [file...]
tsv-join matches input lines against lines from a 'filter' file. The match is
based on exact match comparison of one or more 'key' fields. Fields are TAB
delimited by default. Matching lines are written to standard output, along with
any additional fields from the key file that have been specified. An example:
tsv-join --filter-file filter.tsv --key-fields 1 --append-fields 5,6 data.tsv
This reads filter.tsv, creating a hash table keyed on field 1. Lines from data.tsv
are read one at a time. If field 1 is found in the hash table, the line is written
to standard output with fields 5 and 6 from the filter file appended. In database
parlance this is a "hash semi join". Note the asymmetric relationship: Records in
the filter file should be unique, but data.tsv lines can repeat.
tsv-join can also work as a simple filter, this is the default behavior. Example:
tsv-join --filter-file filter.tsv data.tsv
This outputs all lines from data.tsv found in filter.tsv. --key-fields can still
be used to define the match key. The --exclude option can be used to exclude
matched lines rather than keep them.
Multiple fields can be specified as keys and append fields. Field numbers start
at one, zero represents the whole line. Fields are comma separated and ranges
can be used. Example:
tsv-join -f filter.tsv -k 1,2 --append-fields 3-7 data.tsv
Options:
EOS";
tsv_join
functionsstructsvariables