Syntax
tagextract [-h][-v][-n number ][-m [ fieldname op [fieldvalue]]]...
[infile][outfile]
Description
tagextract processes a tag stream on its standard input, looking for
records which match the conditions required by the fieldname, operator
and usually fieldvalue arguments.
Modifier flags
- -h
- Disables normal header processing. If this is not present then
the first record is assumed to be a header, and will always be output
intact as the new header record.
- -v
- Invert the sense of matching, to output all the lines which do
NOT match the conditions.
- -d
- Print debugging information to stderr
- -n
- Output the record which is this number of records into the tag file
later versions may expand this to select a range. Record 0 is the header.
Conditions
Most condition tests are of the form
fieldname operator value
but some do not require the value.
The operators are
- -eq
- String equals
- ==
- Numerically equal (like in Perl)
- -gt
- Numerically greater than (unlike Perl)
- -lt
- Numerically less than (unlike Perl)
- -contains
- Contains
- -exists
- True if the field exists in the record - does not take a value
- -before
- True if the field with the given value has not yet been reached