-
- dss - scan a data stream and apply a select expression to each record
-
- dss [ options ] [ expression ] [ file ... ]
-
- dss scans a record-oriented data stream, applies a select expression to each record, and writes the
matching records to the standard output. If expression is - or empty then all records match. If file
is - or omitted then the standard input is read. If |{write format} is not specified then the
output format is the same as the format of the first input file.
- Input files are vczip(1), gzip(1),
bzip2(1) or pzip(1)
decompressed if necessary.
-
- Query expressions support C-style syntax. Strings may be specified with '...', "..." or /.../ delimiters. =~
and !~ operations on strings treat the right hand operand as a possibly field-specific matching pattern. string
field matching patterns are extended regex(3) regular
expressions (egrep(1) style.)
- An expression of the form { query [--option...] [arg...] [> output] } accesses the
compiled query defined in a --library dynamic library. { query --man } lists the
documentation for query.
- Dynamic queries enclosed in {...} and interpreted queries enclosed in (...) may be composed using the |, ?:
, and ; operators. A|B specifies that query B processes records selected by query A
. A?B:C specifies that query B processes the records selected by query A and
query C processes the records not selected by query A; query B may be omitted. A;B
specifies that queries A and B process the same records.
- NOTE:
- Specify --method=method for a list of supported variables.
-
- -a, --append
- Open output files in append mode. This disables file header output.
- -d, --debug
- Enable debug tracing.
- -i, --info
- List library information for each file operand in --man style on standard
error. The expression operand is not specified in this case. If no file operands are specified then the
first instance of each dss library installed on $PATH or a sibling dir on $PATH is listed.
- -I, --include=dir
- Add dir to the list of directories searched for include files. The
default ../lib/dss directories on $PATH are added to this list.
- -l, --library=name
- Load the dynamic library name. dss libraries may define
methods, types, maps or queries.
- -m, --map
- Numeric field value map XML file. --method=dss,man describes the <MAP>
tag.
- -q, --quiet
- Disable non-fatal warning messages.
- -v, --verbose
- Enable verbose status messages.
- -x, --method=method[,option[=value]...][:schema]
- Set the record method. This option must be
specified. The method name may be followed by a , separated list of method specific [no]name[=value] options and
a schema following the first :. Method specific usage may be listed by the man or html method specific
options. Each method is typically implemented in a separate shared library. If the method shared library is not
installed on $PATH or a sibling dir on $PATH then method must be the full path name of the shared
library. The methods, determined by $PATH, are:
- dss
- A pseudo-method that specifies a method, value maps and constraints.
- bgp
- BGP router dump and announce/withdraw messages.
- dibbler
- Dibbler billing data.
- flat
- Fixed-width and/or field-delimited flat file; the method schema is the name of an
XML description file. Public schemas are usually placed in a ../lib/dss sibling directory on $PATH.
- lsa
- ospf lsa logs.
- netflow
- Cisco router netflow dump.
- opaque
- Opaque fixed record data with optional magic. Field names and expressions are
not supported.
- text
- Newline-terminated field-delimited text file; the method schema is a scanf(3)
like format string with embedded field names of the form: %(field1)format-char delimiter ...
- -T, --test=mask
- Enable test code defined by mask. Test code is implementation
specific.
- -c, --count
- Write the matched/total records on the standard output. Deprecated: compose the
expression with |{count} instead.
- -f, --format=format
- Set the output method format. Deprecated: compose the expression with
|{write format} instead.
- -n, --nooutput
- Disable all output. Deprecated: not required when the expression contains a dynamic
query.
- -p, --print=format
- Print selected records according to format. Deprecated: compose
the expression with |{print format} instead.
-
- dss -x dss '{stats --man}'
- List the stats query manpage.
- dss -x bgp '{write --man}'
- List the formats supported by the bgp
method.
- dss -x netflow "{stats --group=prot bytes
packets}" *.gz
- List the stats for the netflow method fields bytes and packets, grouped
by values in the field prot.
- dss -x bgp {count} cisco.dat
- Count the number of bgp
records in cisco.dat.
- a}:{write cisco > b}' mrt.dat">dss -x bgp '(type=="A")?{write
table > a}:{write cisco > o}' mrt.dat
- Write the announce records from mrt.dat to the file a
in the table format and all other records to the file b in the cisco format.
- dss -x foo-txt '{flat
foo-bin}|{compress}' foo.txt > foo.bin
- Convert the foo-txt file foo.txt to the foo-bin
flat method format file foo.bin using the preferred compression method, where foo-txt.dss and
foo-bin.dss are user supplied dss XML schema files describing the input and output formats.
- dss -x foo-bin '(time>="jan 1")|{flat
foo-txt}' foo.bin
- Select all foo.bin records with time > jan 1 and list them in the foo-txt
format.
-
- vczip(1), gzip(1),
bzip2(1), pzip(1),
cql(1)
-
- version
- dss (AT&T Research) 2003-03-27
- author
- Glenn Fowler <gsf@research.att.com
>
- copyright
- Copyright © 2002-2009 AT&T Intellectual Property
- license
- http://www.opensource.org/licenses/cpl1.0.txt