'Bad Substitution' sourcing an auto-completion script as non-root user - bash

Question

I am trying to source an auto-completion script as a non-root user but receive a 'Bad Substitution' error message.
I am able to source it as root though.
On a other server I am able to source the script as non-root user.
I am guessing it is not a permission issue since I receive the same error trying to source a copy of the script with full permissions.
I have tried to echo all the environment variables used in the script, no issue there.
As the auto-completion script is packaged with the software I use I would rather not modify it.
Anyone would have a hint on what could be missing to the user so I can source the script from it ?
Thanks in advance for any idea!
Edit1:
ps output:
PID TTY TIME CMD
3261 pts/0 00:00:00 bash
73620 pts/0 00:00:00 ps
Error only as non-root user:
/opt/splunk/share/splunk/cli-command-completion.sh: 7: /opt/splunk/share/splunk/cli-command-completion.sh: Bad substitution
Script:
# Vainstein K 12aug2013
# # # Check a few prereqs.
feature='"splunk <verb> <object>" tab-completion'
[ `basename $SHELL` != 'bash' ] && echo "Sorry, $feature is only for bash" >&2 && return 11
[ ${BASH_VERSINFO[0]} -lt 4 ] && echo "Sorry, $feature only works with bash 4.0 or higher" >&2 && return 12
[ `type -t complete` != 'builtin' ] && echo "Sorry, $feature requires a bash that supports programmable command completion" >&2 && return 13
die () {
echo "(exit=$?) $#" >&2 && exit 42
}
ifSourced () { # do NOT exit(1) from this function!
local readonly tempfile=`pwd`/tmp--cli-completion--$$
rm -f $tempfile
$BASH ${BASH_ARGV[0]} --populateTempfile $tempfile
[ $? -eq 0 ] || return
[ -e $tempfile ] || return
. $tempfile
rm -f $tempfile
# # # Associate the completion function with the splunk binary.
local readonly completionFunction=fSplunkComplete
complete -r splunk 2>/dev/null
complete -F $completionFunction splunk
# You can view the completion function anytime via: $ type fSplunkComplete
}
ifInvoked () { # all error checking happens in this function
local readonly debug=false
local readonly tempfile=$1
$debug && echo "Told that tempfile=$tempfile"
# # # If anything goes wrong, at least we don't pollute cwd with our tempfile.
$debug || trap "rm -f $tempfile" SIGINT SIGQUIT SIGTERM SIGABRT SIGPIPE
touch $tempfile || die "Cannot touch tempfile=$tempfile"
# # # Decide where SPLUNK_HOME is.
if [ "$(dirname $(pwd))" == 'bin' ]; then
local readonly splunkHome=$(dirname $(dirname $(pwd)))
elif [ -n "$SPLUNK_HOME" ]; then
local readonly splunkHome=$SPLUNK_HOME
else
die 'Cannot figure out where SPLUNK_HOME is'
fi
$debug && echo "Decided SPLUNK_HOME=$splunkHome"
# # # Check that splunk (the binary) exists.
local readonly splunkBinary=$splunkHome/bin/splunk
[ -e $splunkBinary -a -x $splunkBinary ] || die "Cannot find expected binary=$splunkBinary"
# # # Find the file with object->{verb1,verb2,...} map.
local readonly splunkrcCmdsXml=$splunkHome/etc/system/static/splunkrc_cmds.xml
[ -e $splunkrcCmdsXml ] || die "Cannot find expected file $splunkrcCmdsXml"
$debug && echo "Shall read verb-obj info from: $splunkrcCmdsXml"
# # # Parse the map file, and generate our internal verb->{objA,objB,...} map.
local -A verb_to_objects
local line object verb objectsForThisVerb lineNumber=0
local inItem=false
local readonly regex_depr='\<depr\>'
local readonly regex_verb='\<verb\>'
local readonly regex_synonym='\<synonym\>'
while read line; do
lineNumber=$((lineNumber+1))
if $inItem; then
if [[ $line =~ '</item>' ]]; then
$debug && echo "Exited item tag at line=$lineNumber; this was obj=$object"
inItem=false
object=''
elif [[ $line =~ '<cmd name' && ! $line =~ $regex_depr && ! $line =~ $regex_synonym ]]; then
[ -z "$object" ] && die "BUG: No object within item tag. (At line $lineNumber of $splunkrcCmdsXml)"
verb=${line#*\"} # remove shortest match of .*" from the front
verb=${verb%%\"*} # remove longest match of ".* from the back
[ "$verb" == '_internal' ] && continue # Why the... eh, moving on.
objectsForThisVerb=${verb_to_objects[$verb]}
objectsForThisVerb="$objectsForThisVerb $object"
verb_to_objects[$verb]=$objectsForThisVerb
$debug && echo "Mapped object=$object to verb=$verb at line=$lineNumber; now objectsForThisVerb='$objectsForThisVerb'"
fi
else # ! inItem
if [[ $line =~ '<item obj' && ! $line =~ $regex_depr && ! $line =~ $regex_verb && ! $line =~ $regex_synonym ]]; then
inItem=true
object=${line#*\"} # remove shortest match of .*" from the front
object=${object%%\"*} # remove longest match of ".* from the back
$debug && echo "Entered item tag at line=$lineNumber, parsed object=$object"
[ "$object" == 'on' ] && inItem=false # Do not expose Amrit's puerile jest.
[ "$object" == 'help' ] && inItem=false # Although 'help' is a verb, splunkrc_cmds.xml constructs it as an object; ugh. We'll deal with the objects (topics) of 'splunk help' separately, below.
fi
fi
done < $splunkrcCmdsXml
$debug && echo "Processed $lineNumber lines. Map keys: ${!verb_to_objects[*]}, values: ${verb_to_objects[#]}"
# # # Oh wait, '<verb> deploy-server' aren't in splunkrc_cmds.xml; thanks, Jojy!!!!!
for verb in reload enable disable display; do
objectsForThisVerb=${verb_to_objects[$verb]}
objectsForThisVerb="$objectsForThisVerb deploy-server"
verb_to_objects[$verb]=$objectsForThisVerb
done
# # # Find the file with topics understood by 'splunk help <topic>' command, and extract list of topics.
local readonly literalsPy=$splunkHome/lib/python2.7/site-packages/splunk/clilib/literals.py
[ -e $literalsPy ] || die "Cannot find expected file $literalsPy"
$debug && echo "Shall read help topics list from: $literalsPy"
local readonly helpTopics=$(sed '/^addHelp/! d; s/^addHelp//; s/,.*$//; s/[^a-zA-Z_-]/ /g; s/^[ ]*//; s/[ ].*$//; /^$/ d' $literalsPy | sort | uniq)
$debug && echo "Parsed help topics list as: $helpTopics"
#######################################################
# # # Write the completion function to tempfile: BEGIN.
local readonly completionFunction=fSplunkComplete
echo -e 'function '$completionFunction' () {' >> $tempfile
echo -e '\tlocal wordCur=${COMP_WORDS[COMP_CWORD]}' >> $tempfile
echo -e '\tlocal wordPrev=${COMP_WORDS[COMP_CWORD-1]}' >> $tempfile
echo -e '\tcase $wordPrev in' >> $tempfile
# # # What can follow 'splunk' itself? Verbs used in main.c to key the 'cmd_handlers' array; and verbs from splunkrc_cmds.xml; and 'help'.
local readonly keys__cmd_handlers='ftr start startnoss stop restart restartss status rebuild train fsck clean-dispatch clean-srtemp validate verifyconfig anonymize find clean createssl juststopit migrate --version -version version httpport soapport spool ftw envvars _RAW_envvars _port_check cmd _rest_xml_dump search dispatch rtsearch livetail _normalizepath _internal logout btool pooling _web_bootstart offline clone-prep-clear-config diag'
local allVerbs="${!verb_to_objects[*]}"
echo -e '\t\tsplunk)\n\t\t\tCOMPREPLY=( $(compgen -W "'$keys__cmd_handlers $allVerbs' help" -- $wordCur) ) ;;' >> $tempfile
# # # What can follow 'splunk _internal'? see cmd_internal() of main.c
local readonly actions_internal='http mgmt https pre-flight-checks check-db call rpc rpc-auth soap-call soap-call-auth prefixcount totalcount check-xml-files first-time-run make-splunkweb-certs-and-var-run-merged'
echo -e '\t\t_internal)\n\t\t\tCOMPREPLY=( $(compgen -W "'$actions_internal'" -- $wordCur) ) ;;' >> $tempfile
# # # Options to 'splunk clean' are in CLI::clean() of src/main/Clean.cpp; to 'splunk fsck', in usageBanner of src/main/Fsck.cpp; to 'splunk migrate', in CLI::migrate() of src/main/Migration.cpp
echo -e '\t\tclean)\n\t\t\tCOMPREPLY=( $(compgen -W "all eventdata globaldata userdata inputdata locks deployment-artifacts raft" -- $wordCur) ) ;;' >> $tempfile
echo -e '\t\tfsck)\n\t\t\tCOMPREPLY=( $(compgen -W "scan repair clear-bloomfilter make-searchable" -- $wordCur) ) ;;' >> $tempfile
echo -e '\t\tmigrate)\n\t\t\tCOMPREPLY=( $(compgen -W "input-records to-modular-inputs rename-cluster-app" -- $wordCur) ) ;;' >> $tempfile
# # # List the help topics.
echo -e '\t\thelp)\n\t\t\tCOMPREPLY=( $(compgen -W "'$helpTopics'" -- $wordCur) ) ;;' >> $tempfile
# # # What can follow 'splunk cmd'? any executable in SPLUNK_HOME/bin/
echo -e '\t\tcmd)\n\t\t\tCOMPREPLY=( $(compgen -o default -o filenames -G "'$splunkHome'/bin/*" -- $wordCur) ) ;;' >> $tempfile
# # # Finally, let each verb be completed by its objects.
for verb in $allVerbs; do
echo -e '\t\t'$verb')\n\t\t\tCOMPREPLY=( $(compgen -W "'${verb_to_objects[$verb]}'" -- $wordCur) ) ;;' >> $tempfile
done
# # # And if we've run out of suggestions, revert to bash's default completion behavior: filename completion.
echo -e '\t\t*)\n\t\t\tCOMPREPLY=( $(compgen -f -- $wordCur) ) ;;' >> $tempfile
echo -e '\tesac' >> $tempfile
echo -e '}' >> $tempfile
$debug && cp $tempfile $tempfile~bak
# # # Write the completion function to tempfile: DONE.
######################################################
# # # Sanity check: source the tempfile, make sure that the function we wrote can be parsed and loaded by the shell.
unset $completionFunction
. $tempfile
[ "`type -t $completionFunction`" == 'function' ] || die 'BUG: generated completion function cannot be parsed by bash'
}
if [ $SHLVL -eq 1 ]; then
[ $# -ge 1 ] && echo "Ignoring supplied arguments: $#" >&2
ifSourced
elif [ $SHLVL -eq 2 ]; then
if [ $# -eq 2 ] && [ $1 == '--populateTempfile' ]; then
ifInvoked $2
else
echo -e "This script must be sourced, like so:\n\n\t\033[1m. $0\033[0m\n"
fi
else
: # user is running screen(1) or something of the sort.
fi
# # # Clean up.
unset die ifSourced ifInvoked
Edit2:
xtrace output
++ feature='"splunk <verb> <object>" tab-completion'
+++ basename /bin/bash
++ '[' bash '!=' bash ']'
++ '[' 4 -lt 4 ']'
+++ type -t complete
++ '[' builtin '!=' builtin ']'
++ '[' 1 -eq 1 ']'
++ '[' 0 -ge 1 ']'
++ ifSourced
+++ pwd
++ local readonly tempfile=/home/splunk/tmp--cli-completion--12431
++ rm -f /home/splunk/tmp--cli-completion--12431
++ /bin/sh cli-command-completion.sh --populateTempfile /home/splunk/tmp--cli-completion--12431
+ feature="splunk <verb> <object>" tab-completion
+ basename /bin/bash
+ [ bash != bash ]
cli-command-completion.sh: 8: cli-command-completion.sh: Bad substitution
++ '[' 2 -eq 0 ']'
++ return
++ unset die ifSourced ifInvoked
Edit3:
When using
set -o verbose
set -o noglob
set -o noglob
and checking differences between OK (root) and failing (non-root) run.
OK side:
[...]
+++ basename /bin/bash
++ '[' bash '!=' bash ']'
[ ${BASH_VERSINFO[0]} -lt 4 ] && echo "Sorry, $feature only works with bash 4.0 or higher" >&2 && return 12
++ '[' 4 -lt 4 ']'
[...]
++ local readonly tempfile=/home/splunk/tmp--cli-completion--42064
++ rm -f /home/splunk/tmp--cli-completion--42064
++ /bin/bash cli-command-completion.sh --populateTempfile /home/splunk/tmp--cli-completion--42064
+ set -o verbose
set -o noglob
+ set -o noglob
# Vainstein K 12aug2013
[...]
[ ${BASH_VERSINFO[0]} -lt 4 ] && echo "Sorry, $feature only works with bash 4.0 or higher" >&2 && return 12
+ '[' 4 -lt 4 ']'
[...]
Failing side:
[...]
+++ basename /bin/bash
++ '[' bash '!=' bash ']'
[ ${BASH_VERSINFO[0]} -lt 4 ] && echo "Sorry, $feature only works with bash 4.0 or higher" >&2 && return 12
++ '[' 4 -lt 4 ']'
[...]
++ local readonly tempfile=/home/splunk/tmp--cli-completion--40686
++ rm -f /home/splunk/tmp--cli-completion--40686
++ /bin/sh cli-command-completion.sh --populateTempfile /home/splunk/tmp--cli-completion--40686
+ set -o verbose
set -o noglob
+ set -o noglob
# Vainstein K 12aug2013
# # # Check a few prereqs.
feature='"splunk <verb> <object>" tab-completion'
+ feature="splunk <verb> <object>" tab-completion
[ `basename $SHELL` != 'bash' ] && echo "Sorry, $feature is only for bash" >&2 && return 11
+ basename /bin/bash
+ [ bash != bash ]
[ ${BASH_VERSINFO[0]} -lt 4 ] && echo "Sorry, $feature only works with bash 4.0 or higher" >&2 && return 12
cli-command-completion.sh: 10: cli-command-completion.sh: Bad substitution
++ '[' 2 -eq 0 ']'
++ return
# # # Clean up.
unset die ifSourced ifInvoked
++ unset die ifSourced ifInvoked
Seems like as non-root, it runs as /bin/sh whereas as 'bash' as root.
Weird because I tried multiple things to force bash there, maybe not the right ones.
It also fail at line 7 even though the first loop succeeds.

Answer 1

This should do the trick (line 7):
[ $(type -t complete) != 'builtin' ] && echo "Sorry, $feature requires a bash that supports programmable command completion" >&2 && return 13

Answer 2

Turns out from trace output that /bin/sh was used instead of /bin/bash to launch the script because /bin/bash was not set as default shell.
I have changed the default shell to /bin/bash and it is all ok now :)
I have used this method to set /bin/bash as default shell :
Check:
grep /etc/passwd
Change:
chsh --shell /bin/bash
Check modification:
grep /etc/passwd
Thanks for the help!