freebsd-dev/usr.bin/ldd/ldd.1

.\" $FreeBSD$
.\"
.Dd October 23, 2018
.Dt LDD 1
.Os
.Sh NAME
.Nm ldd
.Nd list dynamic object dependencies
.Sh SYNOPSIS
.Nm
.Op Fl a
.Op Fl v
.Op Fl f Ar format
.Ar program ...
.Sh DESCRIPTION
The
.Nm
utility displays all shared objects that are needed to run the given program or
to load the given shared object.
Contrary to
.Xr nm 1 ,
the list includes
.Dq indirect
dependencies that are the result of needed shared objects which themselves
depend on yet other shared objects.
.Pp
Zero, one or two
.Fl f
options may be given.
The argument is a format string passed to
.Xr rtld 1
and allows customization of
.Nm Ns 's
output.
If one is given, it sets
.Ev LD_TRACE_LOADED_OBJECTS_FMT1 .
If two are given, they set
.Ev LD_TRACE_LOADED_OBJECTS_FMT1
and
.Ev LD_TRACE_LOADED_OBJECTS_FMT2 ,
respectively.
See
.Xr rtld 1
for details, including a list of recognized conversion characters.
.Pp
The
.Fl a
option displays the list of all objects that are needed by each loaded
object.
This option does not work with
.Xr a.out 5
binaries.
.Pp
The
.Fl v
option displays a verbose listing of the dynamic linking headers
encoded in the executable.
See the source code and include
files for the definitive meaning of all the fields.
.Sh IMPLEMENTATION NOTES
.Nm
lists the dependencies of an executable by setting
.Xr rtld 1
environment variables and running the executable in a child process.
If the executable is corrupt or invalid,
.Nm
may therefore fail without providing any diagnostic error messages.
.Sh EXAMPLES
The following is an example of a shell pipeline which uses the
.Fl f
option.
It will print a report of all ELF binaries in the current directory,
which link against libc.so.6:
.Dl "find . -type f | xargs -n1 file -F ' ' | grep 'ELF.*dynamically' | cut -f1 -d' ' | xargs ldd -f '%A %o\en' | grep libc.so.6"
.Sh SEE ALSO
.Xr ld 1 ,
.Xr nm 1 ,
.Xr readelf 1 ,
.Xr rtld 1
.Sh HISTORY
A
.Nm
utility first appeared in SunOS 4.0, it appeared in its current form in
.Fx 1.1 .
.Pp
The
.Fl v
support is based on code written by
.An John Polstra Aq Mt jdp@polstra.com
Add $FreeBSD$ lines to man pages that are missing them to make it easier for translation teams. PR: docs/13418 Submitted by: Alexey Zelkin <phantom@cris.net> 1999-08-28 23:23:38 +00:00			`.\" $FreeBSD$`
			`.\"`
Add an IMPLEMENTATION NOTES section to ldd.1. PR: 231926 Reviewed by: emaste MFC after: 1 month 2018-10-23 13:49:53 +00:00			`.Dd October 23, 2018`
Imported NetBSD's ld for shared libs. 1993-11-03 23:41:59 +00:00			`.Dt LDD 1`
mdoc(7) police: removed HISTORY info from the .Os call. 2001-07-10 14:16:33 +00:00			`.Os`
Imported NetBSD's ld for shared libs. 1993-11-03 23:41:59 +00:00			`.Sh NAME`
			`.Nm ldd`
			`.Nd list dynamic object dependencies`
			`.Sh SYNOPSIS`
mdoc(7) police: use the new features of the Nm macro. 2000-11-20 19:21:22 +00:00			`.Nm`
Add support such that if LD_TRACE_LOADED_OBJECTS_ALL is defined to a non-empty string in the environment; we indicate which objects caused each object to be loaded. PR: 30908 Submitted-by: Mike Meyer <mwm@mired.org> 2002-02-17 07:04:32 +00:00			`.Op Fl a`
Incorporate John Polstra's sods.c display of the details about the dynamic linking information in the executable. It's quite extensive. It's connected to ldd's (new) -v option. 1996-10-01 02:16:16 +00:00			`.Op Fl v`
Made the synopsis in the man page conform to the style guide. Made the usage message conform to the style guide. Don't use the implementation variable `__progname'. 1996-11-30 16:12:46 +00:00			`.Op Fl f Ar format`
Support for specifying printf-like output specs to control the ldd output as present in the new rtld version. Obtained from: NetBSD Reviewed by: nate, jdp 1996-10-01 01:34:32 +00:00			`.Ar program ...`
Imported NetBSD's ld for shared libs. 1993-11-03 23:41:59 +00:00			`.Sh DESCRIPTION`
Use `The .Nm utility' 2002-04-20 12:18:28 +00:00			`The`
Corractly use .Nm and .An/.Aq macros. Replace FreeBSD with .Fx macro e. 2000-05-10 15:46:27 +00:00			`.Nm`
Use `The .Nm utility' 2002-04-20 12:18:28 +00:00			`utility displays all shared objects that are needed to run the given program or`
Allow ldd(1) be used on shared libraries in addition to executables. 2002-02-04 10:33:48 +00:00			`to load the given shared object.`
Corractly use .Nm and .An/.Aq macros. Replace FreeBSD with .Fx macro e. 2000-05-10 15:46:27 +00:00			`Contrary to`
			`.Xr nm 1 ,`
			`the list includes`
Imported NetBSD's ld for shared libs. 1993-11-03 23:41:59 +00:00			`.Dq indirect`
fix a few spelling changes Submitted by: Josh Gilliam Closes PR's: 4429, 4431-4438 PS: He has agreed to submit all contrib fixes back to the original author. 1997-08-30 12:22:49 +00:00			`dependencies that are the result of needed shared objects which themselves`
Imported NetBSD's ld for shared libs. 1993-11-03 23:41:59 +00:00			`depend on yet other shared objects.`
Support for specifying printf-like output specs to control the ldd output as present in the new rtld version. Obtained from: NetBSD Reviewed by: nate, jdp 1996-10-01 01:34:32 +00:00			`.Pp`
			`Zero, one or two`
			`.Fl f`
Remove single-space hard sentence breaks. These degrade the quality of the typeset output, tend to make diffs harder to read and provide bad examples for new-comers to mdoc. 2000-03-01 12:20:22 +00:00			`options may be given.`
			`The argument is a format string passed to`
Support for specifying printf-like output specs to control the ldd output as present in the new rtld version. Obtained from: NetBSD Reviewed by: nate, jdp 1996-10-01 01:34:32 +00:00			`.Xr rtld 1`
			`and allows customization of`
Corractly use .Nm and .An/.Aq macros. Replace FreeBSD with .Fx macro e. 2000-05-10 15:46:27 +00:00			`.Nm Ns 's`
Remove single-space hard sentence breaks. These degrade the quality of the typeset output, tend to make diffs harder to read and provide bad examples for new-comers to mdoc. 2000-03-01 12:20:22 +00:00			`output.`
Expand documentation of -f option PR: docs/66265 Submitted by: Michel Lavondes <fox@vader.aacc.cc.md.us> MFC after: 1 week 2007-05-12 12:23:40 +00:00			`If one is given, it sets`
			`.Ev LD_TRACE_LOADED_OBJECTS_FMT1 .`
			`If two are given, they set`
			`.Ev LD_TRACE_LOADED_OBJECTS_FMT1`
			`and`
			`.Ev LD_TRACE_LOADED_OBJECTS_FMT2 ,`
			`respectively.`
Remove single-space hard sentence breaks. These degrade the quality of the typeset output, tend to make diffs harder to read and provide bad examples for new-comers to mdoc. 2000-03-01 12:20:22 +00:00			`See`
Support for specifying printf-like output specs to control the ldd output as present in the new rtld version. Obtained from: NetBSD Reviewed by: nate, jdp 1996-10-01 01:34:32 +00:00			`.Xr rtld 1`
Expand documentation of -f option PR: docs/66265 Submitted by: Michel Lavondes <fox@vader.aacc.cc.md.us> MFC after: 1 week 2007-05-12 12:23:40 +00:00			`for details, including a list of recognized conversion characters.`
Incorporate John Polstra's sods.c display of the details about the dynamic linking information in the executable. It's quite extensive. It's connected to ldd's (new) -v option. 1996-10-01 02:16:16 +00:00			`.Pp`
			`The`
Add support such that if LD_TRACE_LOADED_OBJECTS_ALL is defined to a non-empty string in the environment; we indicate which objects caused each object to be loaded. PR: 30908 Submitted-by: Mike Meyer <mwm@mired.org> 2002-02-17 07:04:32 +00:00			`.Fl a`
			`option displays the list of all objects that are needed by each loaded`
mdoc(7) police: kill hard sentence breaks. 2002-03-15 15:31:54 +00:00			`object.`
			`This option does not work with`
Add support such that if LD_TRACE_LOADED_OBJECTS_ALL is defined to a non-empty string in the environment; we indicate which objects caused each object to be loaded. PR: 30908 Submitted-by: Mike Meyer <mwm@mired.org> 2002-02-17 07:04:32 +00:00			`.Xr a.out 5`
			`binaries.`
			`.Pp`
			`The`
Incorporate John Polstra's sods.c display of the details about the dynamic linking information in the executable. It's quite extensive. It's connected to ldd's (new) -v option. 1996-10-01 02:16:16 +00:00			`.Fl v`
Fix typos, mostly s/ an / a / where appropriate and a few s/an/and/ Add FreeBSD Id tag where missing. 2002-12-30 21:18:15 +00:00			`option displays a verbose listing of the dynamic linking headers`
mdoc(7) police: kill hard sentence breaks. 2002-03-15 15:31:54 +00:00			`encoded in the executable.`
			`See the source code and include`
Incorporate John Polstra's sods.c display of the details about the dynamic linking information in the executable. It's quite extensive. It's connected to ldd's (new) -v option. 1996-10-01 02:16:16 +00:00			`files for the definitive meaning of all the fields.`
Add an IMPLEMENTATION NOTES section to ldd.1. PR: 231926 Reviewed by: emaste MFC after: 1 month 2018-10-23 13:49:53 +00:00			`.Sh IMPLEMENTATION NOTES`
			`.Nm`
			`lists the dependencies of an executable by setting`
			`.Xr rtld 1`
			`environment variables and running the executable in a child process.`
			`If the executable is corrupt or invalid,`
			`.Nm`
			`may therefore fail without providing any diagnostic error messages.`
Add an example of how to use ldd -f. 2008-05-15 10:43:11 +00:00			`.Sh EXAMPLES`
			`The following is an example of a shell pipeline which uses the`
			`.Fl f`
			`option.`
			`It will print a report of all ELF binaries in the current directory,`
			`which link against libc.so.6:`
ldd: avoid statically linked executables in example The example works but spews warnings if run over a directory with statically linked binaries. PR: 211024 Submitted by: mike@skew.org 2017-12-23 19:48:57 +00:00			`.Dl "find . -type f \| xargs -n1 file -F ' ' \| grep 'ELF.*dynamically' \| cut -f1 -d' ' \| xargs ldd -f '%A %o\en' \| grep libc.so.6"`
Imported NetBSD's ld for shared libs. 1993-11-03 23:41:59 +00:00			`.Sh SEE ALSO`
			`.Xr ld 1 ,`
Cross-reference ldd(1) in rtld(1) and vice versa. 2000-03-28 09:01:04 +00:00			`.Xr nm 1 ,`
Add an IMPLEMENTATION NOTES section to ldd.1. PR: 231926 Reviewed by: emaste MFC after: 1 month 2018-10-23 13:49:53 +00:00			`.Xr readelf 1 ,`
Cross-reference ldd(1) in rtld(1) and vice versa. 2000-03-28 09:01:04 +00:00			`.Xr rtld 1`
Imported NetBSD's ld for shared libs. 1993-11-03 23:41:59 +00:00			`.Sh HISTORY`
			`A`
Corractly use .Nm and .An/.Aq macros. Replace FreeBSD with .Fx macro e. 2000-05-10 15:46:27 +00:00			`.Nm`
			`utility first appeared in SunOS 4.0, it appeared in its current form in`
			`.Fx 1.1 .`
Incorporate John Polstra's sods.c display of the details about the dynamic linking information in the executable. It's quite extensive. It's connected to ldd's (new) -v option. 1996-10-01 02:16:16 +00:00			`.Pp`
			`The`
			`.Fl v`
Corractly use .Nm and .An/.Aq macros. Replace FreeBSD with .Fx macro e. 2000-05-10 15:46:27 +00:00			`support is based on code written by`
use .Mt to mark up email addresses consistently (part3) PR: 191174 Submitted by: Franco Fichtner <franco at lastsummer.de> 2014-06-23 08:23:05 +00:00			`.An John Polstra Aq Mt jdp@polstra.com`