'\" te
.\" Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
.TH elfcompress 1 "23 April 2014" "SunOS 5.11" "User Commands"
.SH NAME
elfcompress \- compress/decompress debug sections of an object file
.SH SYNOPSIS
.LP
.nf
\fBelfcompress\fR [\fB-fV\fR] [\fB-t\fR \fItype\fR] \fIfilename\fR...
.fi

.SH DESCRIPTION
.sp
.LP
The \fBelfcompress\fR command is used to compress or decompress debug sections in \fBELF\fR object files. Unless otherwise specified, all debug and annotate sections are manipulated.
.sp
.LP
If the input file is an archive (see \fBar.h\fR(3HEAD)), the archive is treated as a set of individual files. If the archive member is not an object file, then it is left unchanged.
.sp
.LP
\fBelfcompress\fR cannot modify a section that is contained within a segment. Such allocable sections have their \fBSHF_ALLOC\fR section flag set. \fBelfcompress\fR cannot modify sections of type \fBSHT_NOBITS\fR. The compression operation specified with the\fB-t\fR option may place additional limits on candidate sections. See the \fB-t\fR option, and NOTES.
.sp
.LP
When the \fB-n\fR option is used to specify one or more sections to process, only the specified sections are processed, and all other sections are left unmodified. When the \fB-n\fR option is not used, \fBelfcompress\fR selects all sections that are compatible with the compression operation specified with the \fB-t\fR option.
.SH OPTIONS
.sp
.LP
The following options are supported:
.sp
.ne 2
.mk
.na
\fB\fB-f\fR\fR
.ad
.sp .6
.RS 4n
By default, \fBelfcompress\fR will only compress sections if their resulting size is equal to or smaller than the original data. Specify \fB-f\fR to force compression even when the resulting size is larger than the original.
.RE

.sp
.ne 2
.mk
.na
\fB\fB-n\fR \fIname\fR\fR
.ad
.sp .6
.RS 4n
Specifies the name of the section to process. \fBelfcompress\fR can take multiple \fB-n\fR options to allow for specification of multiple sections. If \fB-n\fR is not used, \fBelfcompress\fR selects all debug sections that are compatible with the specified compression operation. See the \fB-t\fR option, and NOTES.
.RE

.sp
.ne 2
.mk
.na
\fB\fB-t\fR \fItype\fR\fR
.ad
.sp .6
.RS 4n
Specifies the compression operation to be performed. The following compression types are recognized.
.sp
.ne 2
.mk
.na
\fB\fBnone\fR\fR
.ad
.sp .6
.RS 4n
Compressed sections are decompressed.
.RE

.sp
.ne 2
.mk
.na
\fB\fBzlib\fR\fR
.ad
.sp .6
.RS 4n
Compress debug sections with \fBZLIB\fR compression. Candidate sections must be non-allocable (\fBSHF_ALLOC\fR flag not set) and have a section type of \fBSHT_PROGBITS\fR, \fBSHT_SUNW_DEBUG\fR, \fBSHT_SUNW_DEBUGSTR\fR, or \fBSHT_SUNW_ANNOTATE\fR. The resulting sections will have the \fBSHF_COMPRESSED\fR section flag set to identify the use of compression.
.RE

.sp
.ne 2
.mk
.na
\fB\fBzlib-gnu\fR\fR
.ad
.sp .6
.RS 4n
Compress debug sections with \fBZLIB\fR compression, using the \fBGNU\fR section compression format. Candidate sections must be non-allocable (\fBSHF_ALLOC\fR flag not set), cannot have type \fBSHT_NOBITS\fR, and must have a name that begins with \fB\&.debug\fR. The resulting section will be renamed to start with \fB\&.zdebug\fR, to identify the use of compression.
.RE

If the \fB-t\fR option is not specified, the effect is equivalent to specifying \fB-t\fR \fBzlib\fR.
.RE

.sp
.ne 2
.mk
.na
\fB\fB-V\fR\fR
.ad
.sp .6
.RS 4n
Prints a message on standard error giving information about the version of \fBelfcompress\fR.
.RE

.SH NOTES
.sp
.LP
The \fBzlib-gnu\fR compression format is limited to sections with names that start with \fB\&.debug\fR, while the default \fBzlib\fR compression format can be applied to sections with arbitrary names. When \fB-t\fR \fBzlib-gnu\fR is specified, and the \fB-n\fR option is not, any previously compressed sections with names that are incompatible with the \fBzlib-gnu\fR format are decompressed.
.SH EXAMPLES
.LP
\fBExample 1 \fRApply \fBzlib\fR compression to all debug sections
.sp
.in +2
.nf
% \fBelfcompress file\fR
.fi
.in -2
.sp

.LP
\fBExample 2 \fRDecompress all debug sections
.sp
.in +2
.nf
% \fBelfcompress -t none file\fR
.fi
.in -2
.sp

.LP
\fBExample 3 \fRCompress the \fB\&.debug_info\fR section, using the \fBGNU\fR-style format
.sp
.in +2
.nf
% \fBelfcompress -t zlib-gnu -n .debug_info file\fR
.fi
.in -2
.sp

.SH FILES
.sp
.ne 2
.mk
.na
\fB\fB/tmp/elfcompress*\fR\fR
.ad
.RS 21n
.rt  
temporary files
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Availabilitydeveloper/base-developer-utilities
_
Interface StabilityCommitted
.TE

.SH SEE ALSO
.sp
.LP
\fBar\fR(1), \fBas\fR(1), \fBld\fR(1), \fBmcs\fR(1), \fBstrip\fR(1), \fBar.h\fR(3HEAD), \fBelf\fR(3ELF), \fBzlib\fR(3), \fBa.out\fR(4), \fBattributes\fR(5)
.sp
.LP
\fIOracle Solaris 11.3 Linkers and Libraries         Guide\fR