percona-toolkit 2.2.7-1~dfsg1 / usr / bin / pt-pmp

#!/usr/bin/env bash

# This program is part of Percona Toolkit: http://www.percona.com/software/
# See "COPYRIGHT, LICENSE, AND WARRANTY" at the end of this file for legal
# notices and disclaimers.

TOOL="pt-pmp"

# ###########################################################################
# log_warn_die package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/bash/log_warn_die.sh
#   t/lib/bash/log_warn_die.sh
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################


set -u

PTFUNCNAME=""
PTDEBUG="${PTDEBUG:-""}"
EXIT_STATUS=0

ts() {
   TS=$(date +%F-%T | tr ':-' '_')
   echo "$TS $*"
}

info() {
   [ ${OPT_VERBOSE:-3} -ge 3 ] && ts "$*"
}

log() {
   [ ${OPT_VERBOSE:-3} -ge 2 ] && ts "$*"
}

warn() {
   [ ${OPT_VERBOSE:-3} -ge 1 ] && ts "$*" >&2
   EXIT_STATUS=1
}

die() {
   ts "$*" >&2
   EXIT_STATUS=1
   exit 1
}

_d () {
   [ "$PTDEBUG" ] && echo "# $PTFUNCNAME: $(ts "$*")" >&2
}

# ###########################################################################
# End log_warn_die package
# ###########################################################################

# ###########################################################################
# tmpdir package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/bash/tmpdir.sh
#   t/lib/bash/tmpdir.sh
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################


set -u

PT_TMPDIR=""

mk_tmpdir() {
   local dir="${1:-""}"

   if [ -n "$dir" ]; then
      if [ ! -d "$dir" ]; then
         mkdir "$dir" || die "Cannot make tmpdir $dir"
      fi
      PT_TMPDIR="$dir"
   else
      local tool="${0##*/}"
      local pid="$$"
      PT_TMPDIR=`mktemp -d -t "${tool}.${pid}.XXXXXX"` \
         || die "Cannot make secure tmpdir"
   fi
}

rm_tmpdir() {
   if [ -n "$PT_TMPDIR" ] && [ -d "$PT_TMPDIR" ]; then
      rm -rf "$PT_TMPDIR"
   fi
   PT_TMPDIR=""
}

# ###########################################################################
# End tmpdir package
# ###########################################################################

# ###########################################################################
# parse_options package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/bash/parse_options.sh
#   t/lib/bash/parse_options.sh
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################





set -u

ARGV=""           # Non-option args (probably input files)
EXT_ARGV=""       # Everything after -- (args for an external command)
HAVE_EXT_ARGV=""  # Got --, everything else is put into EXT_ARGV
OPT_ERRS=0        # How many command line option errors
OPT_VERSION=""    # If --version was specified
OPT_HELP=""       # If --help was specified
PO_DIR=""         # Directory with program option spec files

usage() {
   local file="$1"

   local usage="$(grep '^Usage: ' "$file")"
   echo $usage
   echo
   echo "For more information, 'man $TOOL' or 'perldoc $file'."
}

usage_or_errors() {
   local file="$1"

   if [ "$OPT_VERSION" ]; then
      local version=$(grep '^pt-[^ ]\+ [0-9]' "$file")
      echo "$version"
      return 1
   fi

   if [ "$OPT_HELP" ]; then
      usage "$file"
      echo
      echo "Command line options:"
      echo
      perl -e '
         use strict;
         use warnings FATAL => qw(all);
         my $lcol = 20;         # Allow this much space for option names.
         my $rcol = 80 - $lcol; # The terminal is assumed to be 80 chars wide.
         my $name;
         while ( <> ) {
            my $line = $_;
            chomp $line;
            if ( $line =~ s/^long:/  --/ ) {
               $name = $line;
            }
            elsif ( $line =~ s/^desc:// ) {
               $line =~ s/ +$//mg;
               my @lines = grep { $_      }
                           $line =~ m/(.{0,$rcol})(?:\s+|\Z)/g;
               if ( length($name) >= $lcol ) {
                  print $name, "\n", (q{ } x $lcol);
               }
               else {
                  printf "%-${lcol}s", $name;
               }
               print join("\n" . (q{ } x $lcol), @lines);
               print "\n";
            }
         }
      ' "$PO_DIR"/*
      echo
      echo "Options and values after processing arguments:"
      echo
      (
         cd "$PO_DIR"
         for opt in *; do
            local varname="OPT_$(echo "$opt" | tr a-z- A-Z_)"
            eval local varvalue=\$$varname
            if ! grep -q "type:" "$PO_DIR/$opt" >/dev/null; then
               if [ "$varvalue" -a "$varvalue" = "yes" ];
                  then varvalue="TRUE"
               else
                  varvalue="FALSE"
               fi
            fi
            printf -- "  --%-30s %s" "$opt" "${varvalue:-(No value)}"
            echo
         done
      )
      return 1
   fi

   if [ $OPT_ERRS -gt 0 ]; then
      echo
      usage "$file"
      return 1
   fi

   return 0
}

option_error() {
   local err="$1"
   OPT_ERRS=$(($OPT_ERRS + 1))
   echo "$err" >&2
}

parse_options() {
   local file="$1"
   shift

   ARGV=""
   EXT_ARGV=""
   HAVE_EXT_ARGV=""
   OPT_ERRS=0
   OPT_VERSION=""
   OPT_HELP=""
   PO_DIR="$PT_TMPDIR/po"

   if [ ! -d "$PO_DIR" ]; then
      mkdir "$PO_DIR"
      if [ $? -ne 0 ]; then
         echo "Cannot mkdir $PO_DIR" >&2
         exit 1
      fi
   fi

   rm -rf "$PO_DIR"/*
   if [ $? -ne 0 ]; then
      echo "Cannot rm -rf $PO_DIR/*" >&2
      exit 1
   fi

   _parse_pod "$file"  # Parse POD into program option (po) spec files
   _eval_po            # Eval po into existence with default values

   if [ $# -ge 2 ] &&  [ "$1" = "--config" ]; then
      shift  # --config
      local user_config_files="$1"
      shift  # that ^
      local IFS=","
      for user_config_file in $user_config_files; do
         _parse_config_files "$user_config_file"
      done
   else
      _parse_config_files "/etc/percona-toolkit/percona-toolkit.conf" "/etc/percona-toolkit/$TOOL.conf" "$HOME/.percona-toolkit.conf" "$HOME/.$TOOL.conf"
   fi

   _parse_command_line "${@:-""}"
}

_parse_pod() {
   local file="$1"

   PO_FILE="$file" PO_DIR="$PO_DIR" perl -e '
      $/ = "";
      my $file = $ENV{PO_FILE};
      open my $fh, "<", $file or die "Cannot open $file: $!";
      while ( defined(my $para = <$fh>) ) {
         next unless $para =~ m/^=head1 OPTIONS/;
         while ( defined(my $para = <$fh>) ) {
            last if $para =~ m/^=head1/;
            chomp;
            if ( $para =~ m/^=item --(\S+)/ ) {
               my $opt  = $1;
               my $file = "$ENV{PO_DIR}/$opt";
               open my $opt_fh, ">", $file or die "Cannot open $file: $!";
               print $opt_fh "long:$opt\n";
               $para = <$fh>;
               chomp;
               if ( $para =~ m/^[a-z ]+:/ ) {
                  map {
                     chomp;
                     my ($attrib, $val) = split(/: /, $_);
                     print $opt_fh "$attrib:$val\n";
                  } split(/; /, $para);
                  $para = <$fh>;
                  chomp;
               }
               my ($desc) = $para =~ m/^([^?.]+)/;
               print $opt_fh "desc:$desc.\n";
               close $opt_fh;
            }
         }
         last;
      }
   '
}

_eval_po() {
   local IFS=":"
   for opt_spec in "$PO_DIR"/*; do
      local opt=""
      local default_val=""
      local neg=0
      local size=0
      while read key val; do
         case "$key" in
            long)
               opt=$(echo $val | sed 's/-/_/g' | tr '[:lower:]' '[:upper:]')
               ;;
            default)
               default_val="$val"
               ;;
            "short form")
               ;;
            type)
               [ "$val" = "size" ] && size=1
               ;;
            desc)
               ;;
            negatable)
               if [ "$val" = "yes" ]; then
                  neg=1
               fi
               ;;
            *)
               echo "Invalid attribute in $opt_spec: $line" >&2
               exit 1
         esac 
      done < "$opt_spec"

      if [ -z "$opt" ]; then
         echo "No long attribute in option spec $opt_spec" >&2
         exit 1
      fi

      if [ $neg -eq 1 ]; then
         if [ -z "$default_val" ] || [ "$default_val" != "yes" ]; then
            echo "Option $opt_spec is negatable but not default: yes" >&2
            exit 1
         fi
      fi

      if [ $size -eq 1 -a -n "$default_val" ]; then
         default_val=$(size_to_bytes $default_val)
      fi

      eval "OPT_${opt}"="$default_val"
   done
}

_parse_config_files() {

   for config_file in "${@:-""}"; do
      test -f "$config_file" || continue

      while read config_opt; do

         echo "$config_opt" | grep '^[ ]*[^#]' >/dev/null 2>&1 || continue

         config_opt="$(echo "$config_opt" | sed -e 's/^ *//g' -e 's/ *$//g' -e 's/[ ]*=[ ]*/=/' -e 's/[ ]*#.*$//')"

         [ "$config_opt" = "" ] && continue

         if ! [ "$HAVE_EXT_ARGV" ]; then
            config_opt="--$config_opt"
         fi

         _parse_command_line "$config_opt"

      done < "$config_file"

      HAVE_EXT_ARGV=""  # reset for each file

   done
}

_parse_command_line() {
   local opt=""
   local val=""
   local next_opt_is_val=""
   local opt_is_ok=""
   local opt_is_negated=""
   local real_opt=""
   local required_arg=""
   local spec=""

   for opt in "${@:-""}"; do
      if [ "$opt" = "--" -o "$opt" = "----" ]; then
         HAVE_EXT_ARGV=1
         continue
      fi
      if [ "$HAVE_EXT_ARGV" ]; then
         if [ "$EXT_ARGV" ]; then
            EXT_ARGV="$EXT_ARGV $opt"
         else
            EXT_ARGV="$opt"
         fi
         continue
      fi

      if [ "$next_opt_is_val" ]; then
         next_opt_is_val=""
         if [ $# -eq 0 ] || [ $(expr "$opt" : "\-") -eq 1 ]; then
            option_error "$real_opt requires a $required_arg argument"
            continue
         fi
         val="$opt"
         opt_is_ok=1
      else
         if [ $(expr "$opt" : "\-") -eq 0 ]; then
            if [ -z "$ARGV" ]; then
               ARGV="$opt"
            else
               ARGV="$ARGV $opt"
            fi
            continue
         fi

         real_opt="$opt"

         if $(echo $opt | grep '^--no[^-]' >/dev/null); then
            local base_opt=$(echo $opt | sed 's/^--no//')
            if [ -f "$PT_TMPDIR/po/$base_opt" ]; then
               opt_is_negated=1
               opt="$base_opt"
            else
               opt_is_negated=""
               opt=$(echo $opt | sed 's/^-*//')
            fi
         else
            if $(echo $opt | grep '^--no-' >/dev/null); then
               opt_is_negated=1
               opt=$(echo $opt | sed 's/^--no-//')
            else
               opt_is_negated=""
               opt=$(echo $opt | sed 's/^-*//')
            fi
         fi

         if $(echo $opt | grep '^[a-z-][a-z-]*=' >/dev/null 2>&1); then
            val="$(echo $opt | awk -F= '{print $2}')"
            opt="$(echo $opt | awk -F= '{print $1}')"
         fi

         if [ -f "$PT_TMPDIR/po/$opt" ]; then
            spec="$PT_TMPDIR/po/$opt"
         else
            spec=$(grep "^short form:-$opt\$" "$PT_TMPDIR"/po/* | cut -d ':' -f 1)
            if [ -z "$spec"  ]; then
               option_error "Unknown option: $real_opt"
               continue
            fi
         fi

         required_arg=$(cat "$spec" | awk -F: '/^type:/{print $2}')
         if [ "$required_arg" ]; then
            if [ "$val" ]; then
               opt_is_ok=1
            else
               next_opt_is_val=1
            fi
         else
            if [ "$val" ]; then
               option_error "Option $real_opt does not take a value"
               continue
            fi 
            if [ "$opt_is_negated" ]; then
               val=""
            else
               val="yes"
            fi
            opt_is_ok=1
         fi
      fi

      if [ "$opt_is_ok" ]; then
         opt=$(cat "$spec" | grep '^long:' | cut -d':' -f2 | sed 's/-/_/g' | tr '[:lower:]' '[:upper:]')

         if grep "^type:size" "$spec" >/dev/null; then
            val=$(size_to_bytes $val)
         fi

         eval "OPT_$opt"="'$val'"

         opt=""
         val=""
         next_opt_is_val=""
         opt_is_ok=""
         opt_is_negated=""
         real_opt=""
         required_arg=""
         spec=""
      fi
   done
}

size_to_bytes() {
   local size="$1"
   echo $size | perl -ne '%f=(B=>1, K=>1_024, M=>1_048_576, G=>1_073_741_824, T=>1_099_511_627_776); m/^(\d+)([kMGT])?/i; print $1 * $f{uc($2 || "B")};'
}

# ###########################################################################
# End parse_options package
# ###########################################################################

# ###########################################################################
# alt_cmds package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/bash/alt_cmds.sh
#   t/lib/bash/alt_cmds.sh
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################


set -u

_seq() {
   local i="$1"
   awk "BEGIN { for(i=1; i<=$i; i++) print i; }"
}

_pidof() {
   local cmd="$1"
   if ! pidof "$cmd" 2>/dev/null; then
      ps -eo pid,ucomm | awk -v comm="$cmd" '$2 == comm { print $1 }'
   fi
}

_lsof() {
   local pid="$1"
   if ! lsof -p $pid 2>/dev/null; then
      /bin/ls -l /proc/$pid/fd 2>/dev/null
   fi
}



_which() {
   if [ -x /usr/bin/which ]; then
      /usr/bin/which "$1" 2>/dev/null | awk '{print $1}'
   elif which which 1>/dev/null 2>&1; then
      which "$1" 2>/dev/null | awk '{print $1}'
   else
      echo "$1"
   fi
}

# ###########################################################################
# End alt_cmds package
# ###########################################################################

set +u

# Actually does the aggregation.  The arguments are the max number of functions
# to aggregate, and the files to read.  If maxlen=0, it means infinity.  We have
# to pass the maxlen argument into this function to make maxlen testable.
aggregate_stacktrace() {
   local maxlen=$1;
   shift
   awk "
      BEGIN {
         s = \"\";
      }
      /^Thread/ {
         if ( s != \"\" ) {
            print s;
         }
         s = \"\";
         c = 0;
      }
      /^\#/ {
         if ( \$2 ~ /0x/ ) {
            if ( \$4 ~/void|const/ ) {
               targ = \$5;
            }
            else {
               targ = \$4;
               tfile= \$NF;
            }
            if ( targ ~ /[<\\(]/ ) {
               targ = substr(\$0, index(\$0, \" in \") + 4);
               if ( targ ~ / from / ) {
                  targ = substr(targ, 1, index(targ, \" from \") - 1);
               }
               if ( targ ~ / at / ) {
                  targ = substr(targ, 1, index(targ, \" at \") - 1);
               }
               # Shorten C++ templates, e.g. in t/samples/stacktrace-004.txt
               while ( targ ~ />::/ ) {
                  if ( 0 == gsub(/<[^<>]*>/, \"\", targ) ) {
                     break;
                  }
               }
               # Further shorten argument lists.
               while ( targ ~ /\\(/ ) {
                  if ( 0 == gsub(/\\([^()]*\\)/, \"\", targ) ) {
                     break;
                  }
               }
               # Remove void and const decorators.
               gsub(/ ?(void|const) ?/, \"\", targ);
               gsub(/ /, \"\", targ);
            }
            else if ( targ ~ /\\?\\?/ && \$2 ~ /[1-9]/ ) {
               # Substitute ?? by the name of the library.
               targ = \$NF;
               while ( targ ~ /\\// ) {
                  targ = substr(targ, index(targ, \"/\") + 1);
               }
               targ = substr(targ, 1, index(targ, \".\") - 1);
               targ = targ \"::??\";
            }
         }
         else {
            targ = \$2;
         }
         # get rid of long symbol names such as 'pthread_cond_wait@@GLIBC_2.3.2'
         if ( targ ~ /@@/ ) {
            fname = substr(targ, 1, index(targ, \"@@\") - 1);
         }
         else {
            fname = targ;
            if ( tfile ~ /^\// ) {
               last=split(tfile,filen,/\//); 
               fname = targ \"(\" filen[last] \")\";
            }
            else {
               fname = targ
            }
         }
         if ( ${maxlen:-0} == 0 || c < ${maxlen:-0} ) {
            if (s != \"\" ) {
               s = s \",\" fname;
            }
            else {
               s = fname;
            }
         }
         c++;
      }
      END {
         print s
      }
   " "$@" | sort | uniq -c | sort -r -n -k 1,1
}

# The main program to run.
main() {
   local output_file="${OPT_SAVE_SAMPLES:-"$PT_TMPDIR/percona-toolkit"}"

   if [ -z "$ARGV" ]; then
      # There are no files to analyze, so we'll make one.
      if [ -z "$OPT_PID" ]; then
         OPT_PID=$(pidof -s "$OPT_BINARY" 2>/dev/null);
         if [ -z "$OPT_PID" ]; then
            OPT_PID=$(pgrep -o -x "$OPT_BINARY" 2>/dev/null)
         fi
         if [ -z "$OPT_PID" ]; then
            OPT_PID=$(ps -eaf | grep "$OPT_BINARY" | grep -v grep | awk '{print $2}' | head -n1);
         fi
      fi
      date
      for x in $(_seq $OPT_ITERATIONS); do
         gdb -ex "set pagination 0"    \
             -ex "thread apply all bt" \
             -batch                    \
             -p $OPT_PID               \
             >> "$output_file"
         date +'TS %N.%s %F %T' >> "$output_file"
         sleep $OPT_INTERVAL
      done
   fi

   if [ -z "$ARGV" ]; then
      aggregate_stacktrace "$OPT_LINES" "$output_file"
   else
      aggregate_stacktrace "$OPT_LINES" $ARGV
   fi
}

# Execute the program if it was not included from another file.  This makes it
# possible to include without executing, and thus test.
if    [ "${0##*/}" = "$TOOL" ] \
   || [ "${0##*/}" = "bash" -a "${_:-""}" = "$0" ]; then

   mk_tmpdir

   parse_options "$0" "${@:-""}"
   if [ -z "$OPT_HELP" -a -z "$OPT_VERSION" ]; then
      # Validate options
      :
   fi
   usage_or_errors "$0"
   po_status=$?
   if [ $po_status -ne 0 ]; then
      [ $OPT_ERRS -gt 0 ] && exit 1
      exit 0
   fi

   main $ARGV

   rm_tmpdir
fi

# ############################################################################
# Documentation
# ############################################################################
:<<'DOCUMENTATION'
=pod

=head1 NAME

pt-pmp - Aggregate GDB stack traces for a selected program.

=head1 SYNOPSIS

Usage: pt-pmp [OPTIONS] [FILES]

pt-pmp is a poor man's profiler, inspired by L<http://poormansprofiler.org>.
It can create and summarize full stack traces of processes on Linux.
Summaries of stack traces can be an invaluable tool for diagnosing what
a process is waiting for.

=head1 RISKS

Percona Toolkit is mature, proven in the real world, and well tested,
but all database tools can pose a risk to the system and the database
server.  Before using this tool, please:

=over

=item * Read the tool's documentation

=item * Review the tool's known L<"BUGS">

=item * Test the tool on a non-production server

=item * Backup your production server and verify the backups

=back

=head1 DESCRIPTION

pt-pmp performs two tasks: it gets a stack trace, and it summarizes the stack
trace.  If a file is given on the command line, the tool skips the first step
and just aggregates the file.

To summarize the stack trace, the tool extracts the function name (symbol)
from each level of the stack, and combines them with commas.  It does this
for each thread in the output.  Afterwards, it sorts similar threads together
and counts how many of each one there are, then sorts them most-frequent first.

pt-pmp is a read-only tool.  However, collecting GDB stacktraces is achieved by
attaching GDB to the program and printing stack traces from all threads. This
will freeze the program for some period of time, ranging from a second or so to
much longer on very busy systems with a lot of memory and many threads in the
program.  In the tool's default usage as a MySQL profiling tool, this means that
MySQL will be unresponsive while the tool runs, although if you are using the
tool to diagnose an unresponsive server, there is really no reason not to do
this.  In addition to freezing the server, there is also some risk of the server
crashing or performing badly after GDB detaches from it.

=head1 OPTIONS

=over

=item --binary

short form: -b; type: string; default: mysqld

Which binary to trace.

=item --help

Show help and exit.

=item --interval

short form: -s; type: int; default: 0

Number of seconds to sleep between L<"--iterations">.

=item --iterations

short form: -i; type: int; default: 1

How many traces to gather and aggregate.

=item --lines

short form: -l; type: int; default: 0

Aggregate only first specified number of many functions; 0=infinity.

=item --pid

short form: -p; type: int

Process ID of the process to trace; overrides L<"--binary">.

=item --save-samples

short form: -k; type: string

Keep the raw traces in this file after aggregation.

=item --version

Show version and exit.

=back

=head1 ENVIRONMENT

This tool does not use any environment variables.

=head1 SYSTEM REQUIREMENTS

This tool requires Bash v3 or newer.  If no backtrace files are given,
then gdb is also required to create backtraces for the process specified
on the command line.

=head1 BUGS

For a list of known bugs, see L<http://www.percona.com/bugs/pt-pmp>.

Please report bugs at L<https://bugs.launchpad.net/percona-toolkit>.
Include the following information in your bug report:

=over

=item * Complete command-line used to run the tool

=item * Tool L<"--version">

=item * MySQL version of all servers involved

=item * Output from the tool including STDERR

=item * Input files (log/dump/config files, etc.)

=back

If possible, include debugging output by running the tool with C<PTDEBUG>;
see L<"ENVIRONMENT">.

=head1 DOWNLOADING

Visit L<http://www.percona.com/software/percona-toolkit/> to download the
latest release of Percona Toolkit.  Or, get the latest release from the
command line:

   wget percona.com/get/percona-toolkit.tar.gz

   wget percona.com/get/percona-toolkit.rpm

   wget percona.com/get/percona-toolkit.deb

You can also get individual tools from the latest release:

   wget percona.com/get/TOOL

Replace C<TOOL> with the name of any tool.

=head1 AUTHORS

Baron Schwartz, based on a script by Domas Mituzas (L<http://poormansprofiler.org/>)

=head1 ABOUT PERCONA TOOLKIT

This tool is part of Percona Toolkit, a collection of advanced command-line
tools for MySQL developed by Percona.  Percona Toolkit was forked from two
projects in June, 2011: Maatkit and Aspersa.  Those projects were created by
Baron Schwartz and primarily developed by him and Daniel Nichter.  Visit
L<http://www.percona.com/software/> to learn about other free, open-source
software from Percona.

=head1 COPYRIGHT, LICENSE, AND WARRANTY

This program is copyright 2011-2014 Percona LLC and/or its affiliates,
2010-2011 Baron Schwartz.

THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, version 2; OR the Perl Artistic License.  On UNIX and similar
systems, you can issue `man perlgpl' or `man perlartistic' to read these
licenses.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA  02111-1307  USA.

=head1 VERSION

pt-pmp 2.2.7

=cut

DOCUMENTATION