deb-symbols(5)                                               dpkg suite                                              deb-symbols(5)

NAME
       deb-symbols - Debian's extended shared library information file

SYNOPSIS
       DEBIAN/symbols

DESCRIPTION
       The symbol files are shipped in Debian binary packages, and its format is a subset of the template symbol files used by
       dpkg-gensymbols(1) in Debian source packages, see deb-src-symbols(5).

       The format for an extended shared library dependency information entry in these files is:

        library-soname main-dependency-template
        [| alternative-dependency-template]
        [...]
        [* field-name: field-value]
        [...]
         symbol minimal-version [id-of-dependency-template]

       The library-soname is exactly the value of the SONAME field as exported by objdump(1). A dependency-template is a dependency
       where #MINVER# is dynamically replaced either by a version check like “(>= minimal-version)” or by nothing (if an
       unversioned dependency is deemed sufficient).

       Each exported symbol (listed as name@version, with version being “Base” if the library is not versioned) is associated to a
       minimal-version of its dependency template (the main dependency template is always used and will end up being combined with
       the dependency template referenced by id-of-dependency-template if present). The first alternative dependency template is
       numbered 1, the second one 2, etc.  Each column is separated by exactly a single whitespace.

       Each entry for a library can also have some fields of meta-information.  Those fields are stored on lines starting with an
       asterisk. Currently, the only valid fields are:

       Build-Depends-Package
           It indicates the name of the “-dev” package associated to the library and is used by dpkg-shlibdeps to make sure that
           the dependency generated is at least as strict as the corresponding build dependency (since dpkg 1.14.13).

       Build-Depends-Packages
           The same as Build-Depends-Package but accepts a comma-separated list of package names (since dpkg 1.20.0).  This field
           will override any Build-Depends-Package field present, and is mostly useful with “-dev” packages and metapackages
           depending on these, say for a transition period.

       Allow-Internal-Symbol-Groups
           It indicates what internal symbol groups should be ignored, as a whitespace separated list, so that the symbols
           contained in those groups get included in the output file (since dpkg 1.20.1).  This should only be necessary for
           toolchain packages providing those internal symbols. The available groups are system dependent, for ELF and GNU-based
           systems these are aeabi and gomp.

       Ignore-Blacklist-Groups
           A deprecated alias for Allow-Internal-Symbol-Groups (since dpkg 1.20.1, supported since dpkg 1.17.6).

EXAMPLES
   Simple symbols file
        libftp.so.3 libftp3 #MINVER#
         DefaultNetbuf@Base 3.1-1-6
         FtpAccess@Base 3.1-1-6
         [...]

   Advanced symbols file
        libGL.so.1 libgl1
        | libgl1-mesa-glx #MINVER#
        * Build-Depends-Package: libgl1-mesa-dev
         publicGlSymbol@Base 6.3-1
         [...]
         implementationSpecificSymbol@Base 6.5.2-7 1
         [...]

SEE ALSO
       <https://wiki.debian.org/Projects/ImprovedDpkgShlibdeps>, deb-src-symbols(5), dpkg-shlibdeps(1), dpkg-gensymbols(1).

1.21.21                                                      2023-03-02                                              deb-symbols(5)