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pasha19 avatar Ubuntu

Running the same code with -u and +u gives different results

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pasha19

I have a fairly large set of scripts that is the initial part of creating some debug/logging logic for bash scripts. There is a considerable amount of code in the system. Fortunately I can demonstrate the different results that I cannot explain when the script is run +u and -u. Set variables as tested using +u become unset variables when run with -u. The variabl.e name in this case is $FUNCNAME

The short test script are as follows:

#!/bin/bash


### set     -e
### set     -f
### set     -u
### set     -C
### set     -P
### set     -o  pipefail


export  PS4='+:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   '


set     -o  verbose

    #   vXtrap Field Separator  u0081 (plus/minus)
### export  vXtrapLFS='\v'

    #   replacement BASH_SUBSHELL
export  vXtrapSub=()

    #   replacement BASH_SOURCE
export  vXtrapSrc=()

    #   replacement Script
    #       basename "${vXtrapSub[$lIdx]}}" '.sh'
export  vXtrapScr=()

    #   replacement FUNCNAME
export  vXtrapFNm=()

    #   replacement LINENO 
    #       where BASH_LINENO[lIdx] should equal vXtrapLNo[lIdx+1]
export  vXtrapLNo=()

    #   LINENO initiation
    #       line number initial report of function in Debug Trap
export  vXtrapLNI=()

    #   replacement BASH_COMMAND
    #       this is the original unsubstituted source command
    #   the following is a compressed substituted version of the source command
    #       "${vXtrcTrapArg0[$lIdx]} ${vXtrcTrapArgV[$lIdx]}"
export vXtrapCmd=()

    #   replacement BASH_ARGV0
export  vXtrapArg0=()

    #   replacement BASH_ARGVC
export  vXtrapArgC=()

#   replacement BASH_ARGV
#       space delimited
export  vXtrapArgV=()

    #   replacement $?
export  vXtrapRc=()

    #   replacement syserr message
export  vXtrapRcMsg=()

set     +o  verbose

read -rp '090'

#####
#       Transfer Initial command initiation to the revised trace table
#####

i=0
iMax=${#BASH_LINENO[@]}
j=0
k=0
v=''

printf '\n'
v="$BASH_SUBSHELL"
if [[ -z "$v" && -n "${v-_}" ]]; then
    echo '$BASH_SUBSHELL      unset    '"$BASH_SUBSHELL"
else
    echo '$BASH_SUBSHELL      set      '"$BASH_SUBSHELL"
fi

v="$LINENO"
if [[ -z "$v" && -n "${v-_}" ]]; then
    echo '$LINENO             unset    '"$LINENO"
else
    echo '$LINENO             set      '"$LINENO"
fi

v="$BASH_COMMAND"
if [[ -z "$v" && -n "${v-_}" ]]; then
    echo '$BASH_COMMAND       unset    '"$BASH_COMMAND"
else
    echo '$BASH_COMMAND       set      '"$BASH_COMMAND"
fi

for (( i=0; i<=iMax;    i++ ))
do
    printf '\n'

    v="${BASH_SOURCE["$i"]}"
    if [[ -z "$v" && -n "${v-_}" ]]; then
        echo '${BASH_SOURCE['"$i"']}   unset    '"${BASH_SOURCE[$i]}"
    else
        echo '${BASH_SOURCE['"$i"']}   set      '"${BASH_SOURCE[$i]}"
    fi

    v="${FUNCNAME[$i]}"
    if [[ -z "$v" && -n "${v-_}" ]]; then
        echo '${FUNCNAME['"$i"']}      unset    '"${FUNCNAME[$i]}"
    else
        echo '${FUNCNAME['"$i"']}      set      '"${FUNCNAME[$i]}"
    fi

    v="${BASH_LINENO["$i"]}"
    if [[ -z "$v" && -n "${v-_}" ]]; then
        echo '${BASH_LINENO['"$i"']}   unset    '"${BASH_LINENO[$i]}"
    else
        echo '${BASH_LINENO['"$i"']}   set      '"${BASH_LINENO[$i]}"
    fi

    v="${BASH_ARGV0[i]}"
    if [[ -z "$v" && -n "${v-_}" ]]; then
        echo '${BASH_ARGV0['"$i"']}    unset    '"${BASH_ARGV0[$i]}"
    else
        echo '${BASH_ARGV0['"$i"']}    set      '"${BASH_ARGV0[$i]}"
    fi

    v="${BASH_ARGC[i]}"
    if [[ -z "$v" && -n "${v-_}" ]]; then
        echo '${BASH_ARGC['"$i"']}     unset    '"${BASH_ARGC[$i]}"
    else
        echo '${BASH_ARGC['"$i"']}     set      '"${BASH_ARGC[$i]}"
    fi

    j=0
    while [ "$j" -lt "${BASH_ARGC[i]}" ]
    do

        v="${BASH_ARGV["$k"]}"
        if [[ -z "$v" && -n "${v-_}" ]]; then
            echo '${BASH_ARGV['"$i $j"']}   unset  ref=${BASH_ARGV['"$k"']}    '"${BASH_ARGV["$k"]}"
        else
            echo '${BASH_ARGV['"$i $j"']}   set    ref=${BASH_ARGV['"$k"']}    '"${BASH_ARGV["$k"]}"
        fi
        (( k++ ))
        (( j++ ))
    done
done

vPtrapScr="$(basename "${BASH_SOURCE[0]}" '.sh' )"

vPtrapArgC='1'
vPtrapArgV=''
while [ $vPtrapArgC -lt ${BASH_ARGC[0]} ]
do
    case "$vPtrapArgC"  in
        (0)
            vPtrapArgV=" \"${BASH_ARGV["vPtrapArgC"]}\""
            ;;

        (*)
            vPtrapArgV=" \"${BASH_ARGV["$vPtrapArgC"]}\"$vPtrapArgV"
            ;;
    esac


    (( vPtrapArgC++ ))
done

    #   Don't know why FUNCNAME[0] after new terminal is 
    #       '' instead of 'source'
### vPtrapArg0="${FUNCNAME[0]}"
vPtrapArg0='source'

vPtrapCmd="source \"${BASH_SOURCE[0]}\" ${vPtrapArgV}"

vPtrapArgV="\"${BASH_SOURCE[0]}\" ${vPtrapArgV}"

set     -o  xtrace

vXtrapSub=(     "$BASH_SUBSHELL" "$BASH_SUBSHELL"   "$BASH_SUBSHELL" )
vXtrapSrc=(  "${BASH_SOURCE[0]}" ''                  ''              )
vXtrapScr=(         "$vPtrapScr" ''                  ''              )
vXtrapFNm=(                   '' ''                  ''              )
vXtrapLNo=(                  '0' "${BASH_LINENO[0]}" '0'             )
vXtrapLNI=(                  '0' '0'                 '0'             )
    #   values below this line are currently for the calling instruction
    #       when the DEBUG trap activates these will be current script instruction
vXtrapCmd=(        "$vPtrapCmd" "$vPtrapCmd"         ''              )
vXtrapArg0=(      "$vPtrapArg0" "$vPtrapArg0"        ''              )
vXtrapArgC=(      "$vPtrapArgC" "$vPtrapArgC"        '0'             )
vXtrapArgV=(      "$vPtrapArgV" "$vPtrapArgV"        ''              )
vXtrapRc=(                  '0' '0'                  '0'             )
vXtrapRcMsg=(                '' ''                   ''              )

set     +o  xtrace

read -rp '100'

unset   i
unset   iMax
unset   j
unset   k
unset   v
unset   vPtrapScr
unset   vPtrapCmd
unset   vPtrapArg0
unset   vPtrapArgC
unset   vPtrapArgV

read -rp '110'


return  "${vXtrapRc[0]}"

The first run +u has set variables those same variables become unset (specifically $FUNCNAME that prevents the many of the others from being tested) in the -u run.
The test output:

ubuntu@ubuntu:/$ set +u
ubuntu@ubuntu:/$ cd /pool/src/trap/scr
ubuntu@ubuntu:/pool/src/trap/scr$ source SHtest.sh

        #       vXtrap Field Separator  u0081 (plus/minus)
###     export  vXtrapLFS='\v'

        #       replacement BASH_SUBSHELL
export  vXtrapSub=()

        #       replacement BASH_SOURCE
export  vXtrapSrc=()

        #       replacement Script
        #               basename "${vXtrapSub[$lIdx]}}" '.sh'
export  vXtrapScr=()

        #       replacement FUNCNAME
export  vXtrapFNm=()

        #       replacement LINENO 
        #               where BASH_LINENO[lIdx] should equal vXtrapLNo[lIdx+1]
export  vXtrapLNo=()

        #       LINENO initiation
        #               line number initial report of function in Debug Trap
export  vXtrapLNI=()

        #       replacement BASH_COMMAND
        #               this is the original unsubstituted source command
        #       the following is a compressed substituted version of the source command
        #               "${vXtrcTrapArg0[$lIdx]} ${vXtrcTrapArgV[$lIdx]}"
export vXtrapCmd=()

        #       replacement BASH_ARGV0
export  vXtrapArg0=()

        #       replacement BASH_ARGVC
export  vXtrapArgC=()

#       replacement BASH_ARGV
#               space delimited
export  vXtrapArgV=()

        #       replacement $?
export  vXtrapRc=()

        #       replacement syserr message
export  vXtrapRcMsg=()

set             +o      verbose
090

$BASH_SUBSHELL      set      0
$LINENO             set      89
$BASH_COMMAND       set      echo '$BASH_COMMAND       set      '"$BASH_COMMAND"

${BASH_SOURCE[0]}   set      SHtest.sh
${FUNCNAME[0]}      set      
${BASH_LINENO[0]}   set      3
${BASH_ARGV0[0]}    set      /usr/bin/bash
${BASH_ARGC[0]}     set      1
${BASH_ARGV[0 0]}   set    ref=${BASH_ARGV[0]}    SHtest.sh

${BASH_SOURCE[1]}   set      
${FUNCNAME[1]}      set      
${BASH_LINENO[1]}   set      
${BASH_ARGV0[1]}    set      
${BASH_ARGC[1]}     set      0
++:SHtest.sh::184::x::  vXtrapSub=("$BASH_SUBSHELL" "$BASH_SUBSHELL" "$BASH_SUBSHELL")
++:SHtest.sh::185::x::  vXtrapSrc=("${BASH_SOURCE[0]}" '' '')
++:SHtest.sh::186::x::  vXtrapScr=("$vPtrapScr" '' '')
++:SHtest.sh::187::x::  vXtrapFNm=('' '' '')
++:SHtest.sh::188::x::  vXtrapLNo=('0' "${BASH_LINENO[0]}" '0')
++:SHtest.sh::189::x::  vXtrapLNI=('0' '0' '0')
++:SHtest.sh::192::x::  vXtrapCmd=("$vPtrapCmd" "$vPtrapCmd" '')
++:SHtest.sh::193::x::  vXtrapArg0=("$vPtrapArg0" "$vPtrapArg0" '')
++:SHtest.sh::194::x::  vXtrapArgC=("$vPtrapArgC" "$vPtrapArgC" '0')
++:SHtest.sh::195::x::  vXtrapArgV=("$vPtrapArgV" "$vPtrapArgV" '')
++:SHtest.sh::196::x::  vXtrapRc=('0' '0' '0')
++:SHtest.sh::197::x::  vXtrapRcMsg=('' '' '')
++:SHtest.sh::199::x::  set +o xtrace
100
110
ubuntu@ubuntu:/pool/src/trap/scr$ set -u
ubuntu@ubuntu:/pool/src/trap/scr$ source SHtest.sh

        #       vXtrap Field Separator  u0081 (plus/minus)
###     export  vXtrapLFS='\v'

        #       replacement BASH_SUBSHELL
export  vXtrapSub=()

        #       replacement BASH_SOURCE
export  vXtrapSrc=()

        #       replacement Script
        #               basename "${vXtrapSub[$lIdx]}}" '.sh'
export  vXtrapScr=()

        #       replacement FUNCNAME
export  vXtrapFNm=()

        #       replacement LINENO 
        #               where BASH_LINENO[lIdx] should equal vXtrapLNo[lIdx+1]
export  vXtrapLNo=()

        #       LINENO initiation
        #               line number initial report of function in Debug Trap
export  vXtrapLNI=()

        #       replacement BASH_COMMAND
        #               this is the original unsubstituted source command
        #       the following is a compressed substituted version of the source command
        #               "${vXtrcTrapArg0[$lIdx]} ${vXtrcTrapArgV[$lIdx]}"
export vXtrapCmd=()

        #       replacement BASH_ARGV0
export  vXtrapArg0=()

        #       replacement BASH_ARGVC
export  vXtrapArgC=()

#       replacement BASH_ARGV
#               space delimited
export  vXtrapArgV=()

        #       replacement $?
export  vXtrapRc=()

        #       replacement syserr message
export  vXtrapRcMsg=()

set             +o      verbose
090

$BASH_SUBSHELL      set      0
$LINENO             set      89
$BASH_COMMAND       set      echo '$BASH_COMMAND       set      '"$BASH_COMMAND"

${BASH_SOURCE[0]}   set      SHtest.sh
bash: FUNCNAME[$i]: unbound variable
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   vXtrapSub=("$BASH_SUBSHELL" "$BASH_SUBSHELL" "$BASH_SUBSHELL")
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   vXtrapSrc=("${BASH_SOURCE[0]}" '' '')
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   vXtrapScr=("$vPtrapScr" '' '')
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   vXtrapFNm=('' '' '')
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   vXtrapLNo=('0' "${BASH_LINENO[0]}" '0')
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   vXtrapLNI=('0' '0' '0')
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   vXtrapCmd=("$vPtrapCmd" "$vPtrapCmd" '')
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   vXtrapArg0=("$vPtrapArg0" "$vPtrapArg0" '')
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   vXtrapArgC=("$vPtrapArgC" "$vPtrapArgC" '0')
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   vXtrapArgV=("$vPtrapArgV" "$vPtrapArgV" '')
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   vXtrapRc=('0' '0' '0')
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   vXtrapRcMsg=('' '' '')
bash: FUNCNAME[0]: unbound variable
++:${BASH_SOURCE[0]}:${FUNCNAME[0]}:${LINENO[0]}::x::   set +o xtrace
100
110
ubuntu@ubuntu:/pool/src/trap/scr$

I hope this code and output makes sense to those that read it.

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