ltrace(1)						      General Commands Manual							 ltrace(1)

NAME

       ltrace - A library call tracer

SYNOPSIS

       ltrace  [-dfiLSrtttChV]	[-a  column]  [-s  strsize]  [-o  filename]  [-n  nr] [-l filename] [-u username] [-p pid] ... [-e expr] [--debug]
       [--demangle] [--align=column] [--output=filename] [--indent=nr] [--library=filename] [--help] [--version] [command [arg ...]]

DESCRIPTION

       ltrace is a program that simply runs the specified command until it exits.  It intercepts and records the dynamic library calls	which  are
       called  by  the executed process and the signals which are received by that process.  It can also intercept and print the system calls exe-
       cuted by the program.

       Its use is very similar to strace(1).

OPTIONS

       -d, --debug
	      Increase the debugging level.  Use more (ie.  =dd ) for greater debugging information.

       -f     Trace child processes as they are created by currently  traced processes as a result of the fork(2) or clone(2) system  calls.   The
	      new process is attached as soon as its pid is known.

       -i     Print the instruction pointer at the time of the library call.

       -L     DON'T display library calls (use it with the -S option).

       -S     Display system calls as well as library calls

       -r     Print a relative timestamp with each line of the trace.  This records the time difference between the beginning of successive lines.

       -t     Prefix each line of the trace with the time of day.

       -tt    If given twice, the time printed will include the microseconds.

       -ttt   If  given  thrice,  the  time printed will include the microseconds and the leading portion will be printed as the number of seconds
	      since the epoch.

       -C, --demangle
	      Decode (demangle) low-level symbol names into user-level names.  Besides removing any initial underscore prepended  by  the  system,
	      this makes C++ function names readable.

       -a, --align column
	      Align return values in a secific column (default column is 5/8 of screen width).

       -s     Specify the maximum string size to print (the default is 32).

       -o, --output filename
	      Write the trace output to the file filename rather than to stderr.

       -n, --indent nr
	      Indent  trace output by nr number of spaces for each new nested call. Using this option makes the program flow visualization easy to
	      follow.

       -l, --library filename
	      Display only the symbols included in the library filename.  Up to 20 library names can be specified with several instances  of  this
	      option.

       -u username
	      Run  command  with  the  userid,	groupid and supplementary groups of username.  This option is only useful when running as root and
	      enables the correct execution of setuid and/or setgid binaries.

       -p pid Attach to the process with the process ID pid and begin tracing.

       -e expr
	      A qualifying expression which modifies which events to trace.  The format of the expression is:
	      [!]value1[,value2]...
	      where the values are the functions to trace.  Using an exclamation mark negates the set of values.  For example -e printf  means	to
	      trace only the printf library call.  By contrast, -e !printf means to trace every library call except printf.

	      Note  that  some	shells	use the exclamation point for history expansion; even inside quoted arguments.	If so, you must escape the
	      exclamation point with a backslash.

       -h, --help
	      Show a summary of the options to ltrace and exit.

       -V, --version
	      Show the version number of ltrace and exit.

BUGS

       It has most of the bugs stated in strace(1).

       Manual page and documentation are not very up-to-date.

       Option -f sometimes fails to trace some children.

       It only works on Linux/i386, Linux/m68k, Linux/arm, and Linux/S390.

       Only ELF32 binaries are supported.

       If you like to report a bug, send a notice to the author, or use the bug(1) program if you are under the Debian GNU/Linux distribution.

FILES

       /etc/ltrace.conf
	      System configuration file

       ~/.ltrace.conf
	      Personal config file, overrides /etc/ltrace.conf

AUTHOR

       Juan Cespedes <cespedes@debian.org>

SEE ALSO

       strace(1), ptrace(2)

																	 ltrace(1)