NAME
        elf_zscn_compressible

SYNOPSIS
        cc [ flag ... ] file ... -lelf [ library ... ]
        #include <libelf.h>

        int elf_zscn_compressible(Elf_Scn *scn, Elf_ZScn_Type ztype,
            const char *scn_name);

DESCRIPTION
        elf_zscn_compressible is used to determine whether a given
        section can be compressed using a specified compression type.

        The ztype argument specifies the desired compression type, and
        can  be one of the following.

            ELF_ZSCN_T_ZLIB      ZLIB compression, ELF ABI format.

            ELF_ZSCN_T_ZLIB_GNU  ZLIB compression, in the original GNU
                                 format. See NOTES.

        scn_name is the name of the section. It can be set to NULL under
        some circumstances, as described below.

        ELF sections that meet the following requirements can be compressed.

            Non-allocable
                The section must not have the SHF_ALLOC flag set.

            Type
                The section type must be SHT_PROGBITS, SHT_SUNW_DEBUGSTR,
                SHT_SUNW_DEBUG, or SHT_SUNW_ANNOTATE.

            Name
                The ELF_ZSCN_T_ZLIB_GNU compression type requires sections
                to have names starting with .debug. If ELF_ZSCN_T_ZLIB_GNU
                is specified, a non-NULL scn_name argument is required.
'
                For other compression types, it is convention that
                SHT_PROGBITS sections are only compressed if they have
                names that start with .compcom, .debug, .line, or .stab.
                if a non-NULL scn_name is provided, elf_zscn_compressible
                will check for these names. If scn_name is NULL, then
                then any non-allocable section with a valid section type
                is accepted.        

RETURN VALUE
        Upon failure, elf_zscn_compressible returns -1 and sets elf_errno.
        See elf_errno(3ELF). Otherwise, 1 is returned if the section can
        be compressed, and 0 if it cannot. If the section is already
	compressed, elf_zscn_compressible will  return 1 if the section
	could be decompressed, and then recompressed into the desired format.



EXAMPLES
        Example 1 Display compressible sections

        The following code fragment iterates over all the sections
        of an ELF object, and prints the section index and name for
        each section that can be compressed using the ELF_ZSCN_T_ZLIB
        compression type. The details of obtaining the section name,
        and error handling, are omitted in the interest of brevity.

        ndx = 1;
        for (scn = NULL; scn = elf_nextscn(elf, scn); ndx++) {
                scn_name = get_scn_name(...);
                status = elf_zscn_compressible(scn, ELF_ZSCN_T_ZLIB,
                    scn_name);
                if (status == -1)
                        error(...);
                if (status == 1)
                        (void) printf("[%d] %s\n", ndx, scn_name);
        }

NOTES
        The ELF_ZSCN_T_ZLIB_GNU compression type is deprecated, and is
        provided in order to support existing objects. The ELF_ZSCN_T_ZLIB
        type, which is not dependent on section name, is preferred.

        The ELF_ZSCN_T_ZLIB_GNU compression type can only be applied
        to sections with names that start with .debug. The scn_name argument
        is therefore required in order to determine if a section can be
        compressed in this type. If scn_name is NULL, elf_zscn_compressible
        will return 0.

SEE ALSO
       elf_errno(3ELF), elf_zscn_compress(3ELF), elf_zscn_decompress(3ELF),
       elf_zscn_identify(3ELF), libelf(3LIB)