grep Debian control files

       command --copying|-C | --help|-h | --version|-V

       command [options] filter [ file... ]

       where  command  is  one  of  grep-dctrl,  grep-status,  grep-available,
       grep-aptavail and grep-debtags.

       The  grep-dctrl program can answer such questions as What is the Debian
       package foo?, Which version of the Debian package bar is now  current?,
       Which  Debian  packages  does John Doe maintain?, Which Debian packages
       are somehow related to the Scheme programming language?, and with  some
       help,  Who maintain the essential packages of a Debian system?, given a
       useful input file.

       The programs grep-available, grep-status, grep-aptavail  and  grep-deb-
       tags  are  aliases  of (actually, symbolic links to) grep-dctrl.  These
       aliases use as their default input the  dpkg(1)  available  and  status
       files, the apt-cache dumpavail output and the debtags dumpavail output,

       grep-dctrl is a specialised grep program that is meant  for  processing
       any file which has the general format of a Debian package control file,
       as described in the Debian Policy.  These include  the  dpkg  available
       file,  the  dpkg  status file, and the Packages files on a distribution
       medium (such as a Debian CD-ROM or an FTP site carrying Debian).

       You must give a filter expression on  the  command  line.   The  filter
       defines  which  kind of paragraphs (aka package records) are output.  A
       simple filter is a search pattern along with any  options  that  modify
       it.   Possible  modifiers are --eregex, --field, --ignore-case, --regex
       and --exact-match, along  with  their  single-letter  equivalents.   By
       default,  the  search is a case-sensitive fixed substring match on each
       paragraph (in other words, package record) in the input.  With suitable
       modifiers,  this can be changed: the search can be case-insensitive and
       the pattern can be seen as an extended POSIX regular expression.

       Filters can be combined to form more complex filters using the  connec-
       tives  --and,  --or  and  --not.  Parentheses (which usually need to be
       escaped for the shell) can be used for grouping.

       By default, the full matching paragraphs are printed  on  the  standard
       output; specific fields can be selected for output with the -s option.

       After  the  filter  expression comes zero or more file names.  The file
       name - is taken to mean the  standard  input  stream.   The  files  are
       searched  in  order but separately; they are not concatenated together.
       In other words, the end of a file always implies the end of the current

       If  no file names are specified, the program name is used to identify a

   Modifiers of simple filters
       -F field,field, ... | --field=field,field, ...
              Restrict  pattern  matching to the fields given.  Multiple field
              names in one -F option and multiple -F  options  in  one  simple
              filter  are allowed. The search named by the filter will be per-
              formed among all the fields named, and as soon  as  any  one  of
              them matches, the whole simple filter is considered matching.

              A  field specification can contain a colon (:).  In such a case,
              the part up to the colon is taken as the name of the field to be
              searched  in,  and the part after the colon is taken as the name
              of the field whose content is to be used if the field to  search
              in is empty.

       -P     Shorthand for -FPackage.

       -S     Shorthand for -FSource:Package.

       -e, --eregex
              Regard  the  pattern of the current simple filter as an extended
              POSIX regular expression

       -r, --regex
              Regard the pattern of the current simple filter  as  a  standard
              POSIX regular expression.

       -i, --ignore-case
              Ignore  case when looking for a match in the current simple fil-

       -X, --exact-match
              Do an exact match (as opposed to a substring match) in the  cur-
              rent simple filter.

       -w, --whole-pkg
              Do  an extended regular expression match on whole package names,
              assuming the syntax of inter-package relationship fields such as
              Depends,Recommends,  ...  When this flag is given you should not
              worry about sub-package names such as "libpcre3"  also  matching
              "libpcre3-dev". This flag implies (and is incompatible with) -e.

       --eq   Do  an  equality comparison under the Debian version number sys-
              tem.  If the pattern or the field to be searched  in  is  not  a
              valid  Debian  version  number, the paragraph is regarded as not
              matching.  As a special case, this is capable of comparing  sim-
              ple nonnegative integers for equality.

       --lt   Do  an  strictly-less-than  comparison  under the Debian version
              number system.  If the pattern or the field to be searched in is
              not  a valid Debian version number, the paragraph is regarded as
              not matching.  As a special case, this is capable  of  comparing
              simple nonnegative integers.

       --le   Do  an  less-than-or-equal  comparison  under the Debian version
              number system.  If the pattern or the field to be searched in is
              not  a valid Debian version number, the paragraph is regarded as
              not matching.  As a special case, this is capable  of  comparing
              simple nonnegative integers.

   Combining filters
       -!, --not, !
              Match if the following filter does not match.

       -o, --or
              Match  if either one or both of the preceding and following fil-
              ters matches.

       -a, --and
              Match if both the preceding and the following filter match.

       ( ... )
              Parentheses can be used for grouping.  Note that they need to be
              escaped  for  most shells.  Filter modifiers can be given before
              the opening parentheses; they will be treated  as  if  they  had
              been repeated for each simple filter inside the parentheses.

   Output format modifiers
       -s field,field, ... | --show-field=field,field, ...
              Show only the body of these fields from the matching paragraphs.
              The field names must not include any colons or  commas.   Commas
              are  used to delimit field names in the argument to this option.
              The fields are shown in the order  given  here.   See  also  the
              option  -I.   Note  that  in  the absence of the --ensure--dctrl
              option, if only one field is selected, no paragraph separator is

       -I, --invert-show
              Invert  the meaning of option -s: show only the fields that have
              not been named using a -s option.  As an artefact of the  imple-
              mentation,  the order of the fields in the original paragraph is
              not preserved.

       A field specification can contain a colon. In such a case, the part  up
       to  the  colon  is  taken as the name of the field to be shown, and the
       part after the colon is taken as the name of the field whose content is
       to be used if the field to be shown is empty.

       -d     Show  only  the  first  line  of  the Description field from the
              matching paragraphs.  If no -s option is specified, this  option
              also effects -s Description; if there is a -s option but it does
              not include the Description field name, one is appended  to  the
              option.   Thus the Description field's location in the output is
              determined by the -s option, if any, the last  field  being  the

       -n, --no-field-names
              Suppress  field  names when showing specified fields, only their
              bodies are shown.  Each field is printed in  its  original  form
              Output nothing to the standard  output  stream.   Instead,  exit
              immediately after finding the first match.

              Ensure  that  the  output  is in dctrl format, specifically that
              there always is  an  empty  line  separating  paragraphs.   This
              option  is  not  honored  if the -n option has been selected, as
              that option deliberately requests a  non-dctrl  format  for  the
              output.   In  a  future  version,  this  option  may be made the
              default behaviour.

              Override any --ensure-dctrl option given earlier on the  command

              Ignore  errors  in  parsing  input.  A paragraph which cannot be
              parsed is ignored in its entirety, and  the  next  paragraph  is
              assumed  to  start after the first newline since the location of
              the error.

              Show how the current command line has been parsed.

       -l level, --errorlevel=level
              Set log level to level.   level  is  one  of  fatal,  important,
              informational  and  debug,  but  the  last may not be available,
              depending on the compile-time  options.   These  categories  are
              given here in order; every message that is emitted when fatal is
              in effect, will be emitted in the important error level, and  so
              on. The default is important.

       -V, --version
              Print out version information.

       -C, --copying
              Print  out the copyright license.  This produces much output; be
              sure to redirect or pipe it somewhere (such  as  your  favourite

       -h, --help
              Print out a help summary.

       The  almost  simplest use of this program is to print out the status or
       available record of a package.  In this  respect,  grep-dctrl  is  like
       dpkg  -s  or dpkg --print-avail.  To print out the status record of the
       package "mixal", do
       % grep-status -PX mixal
       and to get its available record, use
       % grep-available -PX mixal
       In fact, you can ask for the record of the  "mixal"  package  from  any
       Debian  control  file.   Say, you have the Debian 6.0 CD-ROM's Packages
       % grep-available -F Package foo
       % grep-available -P foo
       which is pretty much the same  thing.   We  can  also  search  in  both
       descriptions and names; if match is found in either, the package record
       is printed:
       % grep-available -P -F Description foo
       % grep-available -F Package -F Description foo
       This kind of search is the exactly same that apt-cache does.

       Here's one thing neither dpkg nor apt-cache do.  Search for a string in
       the  whole  status  or  available file (or any Debian control file, for
       that matter) and print out all package records where we have  a  match.
       % grep-available dpkg
       sometime and watch how thoroughly dpkg has infiltrated Debian.

       All  the  above  queries  were based on simple substring searches.  But
       grep-dctrl can handle regular expressions in the search  pattern.   For
       example, to see the status records of all packages with either "apt" or
       "dpkg" in their names, use
       % grep-status -P -e 'apt|dpkg'

       Now that we have seen all these fine and dandy queries, you might begin
       to  wonder  whether  it is necessary to always see the whole paragraph.
       You may be, for example, interest only in the dependency information of
       the  packages  involved.  Fine.  To show the depends lines of all pack-
       ages maintained by me, do a
       % grep-available -F Maintainer -s Depends ''
       If you want to see the packages' names, too, use
       % grep-available -F Maintainer -s Package,Depends \
       Note that there must be no spaces in the argument to the -s switch.

       More complex queries are also possible.  For example, to see  the  list
       of packages maintained by me and depending on libc6, do
       % grep-available -F Maintainer '' \
          -a -F Depends libc6 -s Package,Depends
       Remember  that  you  can use other UNIX filters to help you, too.  Ever
       wondered, who's the most active Debian developer based on the number of
       source  packages being maintained?  Easy.  You just need to have a copy
       of the most recent Sources file from any Debian mirror.
       % grep-dctrl -n -s Maintainer '' Sources | sort | \
         uniq -c | sort -nr
       This example shows a neat trick: if you want to selectively  show  only
       some field of all packages, just supply an empty pattern.

       The  term  "bogopackage"  means the count of the packages that a Debian
       developer maintains.  To get the bogopackage count for  the  maintainer
       of dctrl-tools, say
       % grep-available -c -FMaintainer \
         "`grep-available -sMaintainer -n -PX dctrl-tools`"

       These examples cover a lot of typical uses of this utility, but not all
       possible  uses.   Use your imagination!  The building blocks are there,
       and if something's missing, let me know.

       In the absence of errors, the exit code 0 is used if at least one match
       was  found,  and  the exit code 1 is used if no matches were found.  If
       there were errors, the exit code is 2, with one exception.  If the  -q,
       --quiet  or  --silent  options are used, the exit code 0 is used when a
       match is found regardless of whether there have been non-fatal errors.

       These messages are emitted in log levels fatal  and  important.   Addi-
       tional  messages may be provided by the system libraries.  This list is

       A pattern is mandatory
              You must specify a pattern to be searched for.

       malformed filter
              No filter was specified, but one is required.

       cannot find enough memory
              More memory was needed than was available.  This  error  may  be
              transient, that is, if you try again, all may go well.

       cannot suppress field names when showing whole paragraphs
              When  you  do  not use the -s switch, grep-dctrl just passes the
              matching paragraphs through, not touching them  any  way.   This
              means, for example, that you can only use -n when you use -s.

       inconsistent modifiers of simple filters
              Conflicting  modifiers of simple filters were used; for example,
              perhaps both -X and -e were specified for the same  simple  fil-

       missing ')' in command line
              There  were  more  opening than closing parentheses in the given

       no such log level
              The argument to -l was invalid.

       too many file names
              The number of file names specified in the command line  exceeded
              a compile-time limit.

       too many output fields
              The  argument to -s had too many field names in it.  This number
              is limited to 256.

       unexpected ')' in command line
              There was no opening parenthesis that would match  some  closing
              parenthesis in the command line.

       Debian  Policy  Manual.  Published as the Debian package debian-policy.
       Also available in the Debian website.

       apt-cache(1), ara(1), dpkg-awk(1), sgrep(1), dpkg(8)

Debian Project                    2012-04-22                     GREP-DCTRL(1)
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