template.sh #13

#!/bin/bash
#==============================================================================
# Copyright and license info is available in the LICENSE file included with
# the Server Deployment Package (SDP), and also available online:
# https://swarm.workshop.perforce.com/projects/perforce-software-sdp/view/main/LICENSE
#------------------------------------------------------------------------------

#==============================================================================
# Declarations and Environment

# Allow override of P4U_HOME, which is set only when testing P4U scripts.
export P4U_HOME="${P4U_HOME:-/p4/common/bin}"
export P4U_LIB="${P4U_LIB:-/p4/common/lib}"
export P4U_ENV="$P4U_LIB/p4u_env.sh"
export VERBOSITY=${VERBOSITY:-3}
export P4U_LOG=Unset

# Environment isolation.  For stability and security reasons, prepend
# PATH to include dirs where known-good scripts exist.
# known/tested PATH and, by implication, executables on the PATH.
export PATH="$P4U_HOME:$PATH:~/bin:."
export P4CONFIG="${P4CONFIG:-.p4config}"

[[ -r "$P4U_ENV" ]] || {
   echo -e "\\nError: Cannot load environment from: $P4U_ENV\\n\\n"
   exit 1
}

declare BASH_LIBS=$P4U_ENV
BASH_LIBS+=" $P4U_LIB/libcore.sh"
BASH_LIBS+=" $P4U_LIB/libp4u.sh"

for bash_lib in $BASH_LIBS; do
   # shellcheck disable=SC1090
   source "$bash_lib" ||\
      { echo -e "\\nFATAL: Failed to load bash lib [$bash_lib]. Aborting.\\n"; exit 1; }
done

declare Version=1.0.0
declare -i SilentMode=0
export VERBOSITY=3

#==============================================================================
# Local Functions

#------------------------------------------------------------------------------
# Function: terminate
function terminate
{
   # Disable signal trapping.
   trap - EXIT SIGINT SIGTERM

   vvmsg "$THISSCRIPT: EXITCODE: $OverallReturnStatus"

   # Stop logging.
   [[ "${P4U_LOG}" == off ]] || stoplog

   # Don't litter.
   cleanTrash

   # With the trap removed, exit.
   exit "$OverallReturnStatus"
}

#------------------------------------------------------------------------------
# Function: usage (required function)
#
# Input:
# $1 - style, either -h (for short form) or -man (for man-page like format).
# The default is -h.
#
# $2 - error message (optional).  Specify this if usage() is called due to
# user error, in which case the given message displayed first, followed by the
# standard usage message (short or long depending on $1).  If displaying an
# errror, usually $1 should be -h so that the longer usage message doesn't
# obsure the error message.
#
# Sample Usage:
# usage
# usage -h
# usage -man
# usage -h "Incorrect command line usage."
#------------------------------------------------------------------------------
function usage
{
   declare style=${1:--h}
   declare errorMessage=${2:-Unset}

   if [[ "$errorMessage" != Unset ]]; then
      echo -e "\\n\\nUsage Error:\\n\\n$errorMessage\\n\\n"
   fi

   echo "USAGE for $THISSCRIPT v$Version:

$THISSCRIPT EDITME <required> literal [-optional] [-L <log>] [-si] [-v<n>] [-n] [-D]

or

$THISSCRIPT [-h|-man|-V]
"
   if [[ $style == -man ]]; then
      echo -e "
DESCRIPTION: EDITME

OPTIONS:
 -v<n>	Set verbosity 1-5 (-v1 = quiet, -v5 = highest).

 -L <log>
	Specify the path to a log file, or the special value 'off' to disable
	logging.  By default, all output (stdout and stderr) goes to
	EDITME_DEFAULT_LOG

	NOTE: This script is self-logging.  That is, output displayed on the screen
	is simultaneously captured in the log file.  Do not run this script with
	redirection operators like '> log' or '2>&1', and do not use 'tee.'

 -si	Operate silently.  All output (stdout and stderr) is redirected to the log
	only; no output appears on the terminal.  This cannot be used with
	'-L off'.
      
	EDITME: This is useful when running from cron, as it prevents automatic
	email from being sent by cron directly, as it does when a script called
	from cron generates any output.  This script is then responsible for
	email handling, if any is to be done.

 -n	No-Op.  Prints commands instead of running them.

 -D     Set extreme debugging verbosity.

HELP OPTIONS:
 -h	Display short help message
 -man	Display man-style help message
 -V	Dispay version info for this script and its libraries.

FILES:

EXAMPLES:

SEE ALSO:
"
   fi

   exit 1
}

#==============================================================================
# Command Line Processing

declare SampleArgument=""; ### EDITME
declare -i shiftArgs=0

set +u
while [[ $# -gt 0 ]]; do
   case $1 in
      (-s) SampleArgument="$2"; shiftArgs=1;; ### EDITME
      (-h) usage -h;;
      (-man) usage -man;;
      (-V) show_versions; exit 1;;
      (-v1) export VERBOSITY=1;;
      (-v2) export VERBOSITY=2;;
      (-v3) export VERBOSITY=3;;
      (-v4) export VERBOSITY=4;;
      (-v5) export VERBOSITY=5;;
      (-L) export P4U_LOG="$2"; shiftArgs=1;;
      (-si) SilentMode=1;;
      (-n) export NO_OP=1;;
      (-D) set -x;; # Debug; use 'set -x' mode.
      (*) usage -h "Unknown arg ($1).";;
   esac

   # Shift (modify $#) the appropriate number of times.
   shift; while [[ $shiftArgs -gt 0 ]]; do
      [[ $# -eq 0 ]] && usage -h "Incorrect number of arguments."
      shiftArgs=$shiftArgs-1
      shift
   done
done
set -u

#==============================================================================
# Command Line Verification

[[ "$SilentMode" -eq 1 && "$P4U_LOG" == off ]] && \
   usage -h "Cannot use '-si' with '-L off'."

[[ "${P4U_LOG:-Unset}" == Unset ]] && \
   P4U_LOG="${LOGS:-/tmp}/${THISSCRIPT%.sh}.$(date +'%Y%m%d-%H%M%S').log"

#==============================================================================
# Main Program

trap terminate EXIT SIGINT SIGTERM

declare -i OverallReturnStatus=0

if [[ "${P4U_LOG}" != off ]]; then
   touch "${P4U_LOG}" || bail "Couldn't touch log file [${P4U_LOG}]."

   # Redirect stdout and stderr to a log file.
   if [[ "$SilentMode" -eq 0 ]]; then
      exec > >(tee "${P4U_LOG}")
      exec 2>&1
   else
      exec >"${P4U_LOG}"
      exec 2>&1
   fi

   initlog
fi

run "ls /tmp" "List temp area."

echo "foo"
echo "bar" >&2

run "ls" "Sample Arg specified with '-s <arg>' is [$SampleArgument].  Directory List:" 1 1

run "/bin/sleep 1" "Taking a short nap." 1 0

# Illustrate stringing together a series of commands using a '|'.
# run can handle this.
run "ls -lrt|grep \"Dec 16\"|head -2|tail -1" "Showing last file:" 1 1

warnmsg "Sample WarningMsg 1"
errmsg "Sample Error Message 2"
warnmsg "Sample WarningMsg 3"
errmsg "Sample Error Message 4"

rrun localhost "sleep 2\\nls -lrt /tmp/" "Doing an ls on simulated remote host." 1 1 0

rrun localhost "ls -l /tmp/*" "Grepping remote output for /tmp/hello" 0 0 "/tmp/hello" ||\
   warnmsg "/tmp/hello was not found in remote output."

if [[ $OverallReturnStatus -eq 0 ]]; then
   msg "${H}\\nAll processing completed successfully.\\n"
else
   msg "${H}\\nProcessing completed, but with errors.  Scan above output carefully.\\n" 
fi

# Illustrate using $SECONDS to display runtime of a script.
msg "That took $((SECONDS/3600)) hours $((SECONDS%3600/60)) minutes $((SECONDS%60)) seconds.\\n"

# See the terminate() function, which is really where this script exits.
exit "$OverallReturnStatus"