Bash script case statement including test conditions not behaving
I have a somewhat lengthy script (main script). I will include it all here as I believe it may be relavent to the answer so please don't hate on me. Everything in this script works. The only thing I am struggling with is case *www1) and *www2) near the end which are essentially the same. The NULL test works and data that is entered into the Zentiy boxes is handled correctly for these cases. However if I enter nothing in the corresponding Zenity fields (invoice_number & note) else until [[ -n "${var2}" ]]; do... is ignored. At the end of the script I have included another more simplified script of just the case in question (simplified). When I run it there is no problem and everything works as expected. The case is just copied over from the original so I am pulling my hair out as to why the one works but not the other. Is someone willing to help on this?
The main script:
#!/bin/bash
work_number="$(zenity --entry --text "ENTER number of work/job entries:" --entry-text "1")"
a=1
until
[[ $work_number -lt $a ]]
do
input="$(zenity --forms --title="table work" --text="Add a new job" --separator="," \
--add-entry="ENTER clientid: " \
--add-entry="ENTER job_start, -t time without time zone, e.g. '11:45:00', seconds allways zero: " \
--add-entry="ENTER job_finish, -t time without time zone, e.g. '11:45:00', seconds allways zero: " \
--add-entry="ENTER number_catchers, -t numeric, must be 0 if no waste has been collected or NULL if it has yet to be assigned to a tip run: " \
--add-entry="ENTER mower_front, -t numeric:" \
--add-entry="ENTER mower_back, -t numeric: " \
--add-entry="ENTER categoryid: " \
--add-entry="ENTER price, -t numeric: " \
--add-entry="ENTER invoice_number, -t text: " \
--add-entry="ENTER note, -t text: " \
--add-entry="ENTER a tip_runid, -t integer: ")"
psql -tA -U chh1 -d crewdb -c "SELECT SETVAL('work_workid_seq', (SELECT MAX(workid) FROM work), true);" >/dev/null 2>&1
dlink="$(psql -tA -U chh1 -d crewdb -c "SELECT MAX(date_linkid) FROM date_link;")"
startt="$(echo "$input" | awk -F, -v OFS=, '{print $2}')"
finisht="$(echo "$input" | awk -F, -v OFS=, '{print $3}')"
st="$( date --date="$startt" +%s 2>/dev/null )"
ft="$( date --date="$finisht" +%s 2>/dev/null )"
if [ -n "$st" -a "$ft" ] ; then
startt="$(date +%H:%M -d "$startt" )"
finisht="$(date +%H:%M -d "$finisht" )"
tzdiff="$(( ft - st ))"
else
tzdiff=0
fi
while [[ ( ( ! "$startt" =~ ^[0-1][0-9]:[0-5][0-9]$ ) && ( ! "$startt" =~ ^[0-2][0-3]:[0-5][0-9]$ ) ) ||
( ( ! "$finisht" =~ ^[0-1][0-9]:[0-5][0-9]$ ) && ( ! "$finisht" =~ ^[0-2][0-3]:[0-5][0-9]$ ) ) ||
( "$tzdiff" -le 0 ) ]];
do
var2="$(zenity --forms --title="job start time and/or job finish time are incorrect" --text "Add a job start time and finish_time" --separator="," \
--add-entry="WARNING! Something went wrong. Please enter a valid job start time, e.g. 8:20: " \
--add-entry="WARNING! Something went wrong. Please enter a valid job finish time, e.g. 12:30: ")"
tzdiff=0
if [ -n "$var2" ] ; then
b1=$(echo "$var2" | cut -d, -f1 )
b2=$(echo "$var2" | cut -d, -f2 )
if [ -n "$b1" -a -n "$b2" ] ; then
tz1=$( date --date="$b1" +%s 2>/dev/null )
tz2=$( date --date="$b2" +%s 2>/dev/null )
if [ -n "$tz1" -a -n "$tz2" ] ; then
startt=$(date +%H:%M -d "$b1" )
finisht=$(date +%H:%M -d "$b2" )
tzdiff=$(( tz2 - tz1 ))
fi
fi
fi
done
var2="$startt,$finisht"
input="$( echo "$input" | awk -v vard="$dlink" -v vart="$var2" 'BEGIN { FS="," } { print $1"xxx1" "," vard"ddd" "," vart "," $4"xxx2" "," $5"xxx3" "," $6"xxx4" "," $7"xxx5" "," $8"xxx6" "," $9"www1" "," $10"www2" "," $11"xxx7" ; }' )"
IFS=, read -ra array1 <<<"$input"
out=""
for i in "${array1[@]}"; do
case "$i" in
*ddd) out="$out,${i/%ddd/}";;
*xxx1) if [[ "${i/%xxx1/}" =~ ^[0-9]+$ ]]; then
out="$out,${i/%xxx1/}"
elif [[ "${i/%xxx1/}" = NULL ]]; then
out="$out,${i/%xxx1/}"
else until [[ ${var2} =~ ^[0-9]+$ ]] || [[ ${var2} = NULL ]]; do
var2="$(zenity --forms --title="clientid field in table work" --text "Add a clientid" --separator="," \
--add-entry="WARNING! You either forgot to enter a clientid or didn't enter a number. Please enter a valid clientid: ")"
done
out="$out,${var2}"
fi
;;
*xxx2) if [[ "${i/%xxx2/}" =~ ^[0-9]+([.][0-9]+)?$ ]]; then
out="$out,${i/%xxx2/}"
elif [[ "${i/%xxx2/}" = NULL ]]; then
out="$out,${i/%xxx2/}"
else until [[ ${var2} =~ ^[0-9]+([.][0-9]+)?$ ]] || [[ ${var2} = NULL ]]; do
var2="$(zenity --forms --title="number of catchers field in table work" --text "Add number of catchers" --separator="," \
--add-entry="WARNING! You either forgot to enter number of catchers or didn't enter a number. Please enter a valid number of catchers: ")"
done
out="$out,${var2}"
fi
;;
*xxx3) if [[ "${i/%xxx3/}" =~ ^[0-9]+$ ]]; then
out="$out,${i/%xxx3/}"
elif [[ "${i/%xxx3/}" = NULL ]]; then
out="$out,${i/%xxx3/}"
else until [[ ${var2} =~ ^[0-9]+$ ]] || [[ ${var2} = NULL ]]; do
var2="$(zenity --forms --title="front mower wheel hight field in table work" --text "Add front mower wheel hight" --separator="," \
--add-entry="WARNING! You either forgot to enter a front mower wheel hight or didn't enter a number. Please enter a valid front mower wheel hight: ")"
done
out="$out,${var2}"
fi
;;
*xxx4) if [[ "${i/%xxx4/}" =~ ^[0-9]+$ ]]; then
out="$out,${i/%xxx4/}"
elif [[ "${i/%xxx4/}" = NULL ]]; then
out="$out,${i/%xxx4/}"
else until [[ ${var2} =~ ^[0-9]+$ ]] || [[ ${var2} = NULL ]]; do
var2="$(zenity --forms --title="back mower wheel hight field in table work" --text "Add back mower wheel hight" --separator="," \
--add-entry="WARNING! You either forgot to enter a back mower wheel hight or didn't enter a number. Please enter a valid back mower wheel hight: ")"
done
out="$out,${var2}"
fi
;;
*xxx5) if [[ "${i/%xxx5/}" =~ ^[0-9]+$ ]]; then
out="$out,${i/%xxx5/}"
elif [[ "${i/%xxx5/}" = NULL ]]; then
out="$out,${i/%xxx5/}"
else until [[ ${var2} =~ ^[0-9]+$ ]] || [[ ${var2} = NULL ]]; do
var2="$(zenity --forms --title="categoryid field in table work" --text "Add a categoryid" --separator="," \
--add-entry="WARNING! You either forgot to enter a categoryid or didn't enter a number. Please enter a valid categoryid: ")"
done
out="$out,${var2}"
fi
;;
*xxx6) if [[ "${i/%xxx6/}" =~ ^[0-9]+([.][0-9]+)?$ ]]; then
out="$out,${i/%xxx6/}"
elif [[ "${i/%xxx6/}" = NULL ]]; then
out="$out,${i/%xxx6/}"
else until [[ ${var2} =~ ^[0-9]+([.][0-9]+)?$ ]] || [[ ${var2} = NULL ]]; do
var2="$(zenity --forms --title="price field in table work" --text "Add price" --separator="," \
--add-entry="WARNING! You either forgot to enter price or didn't enter a number. Please enter a valid price: ")"
done
out="$out,${var2}"
fi
;;
*xxx7) if [[ "${i/%xxx7/}" =~ ^[0-9]+$ ]]; then
out="$out,${i/%xxx7/}"
elif [[ "${i/%xxx7/}" = NULL ]]; then
out="$out,${i/%xxx7/}"
else until [[ ${var2} =~ ^[0-9]+$ ]] || [[ ${var2} = NULL ]]; do
var2="$(zenity --forms --title="tip_runid field in table work" --text "Add a tip_runid" --separator="," \
--add-entry="WARNING! You either forgot to enter a tip_runid or didn't enter a number. Please enter a valid tip_runid: ")"
done
out="$out,${var2}"
fi
;;
*ttt) out="$out,'${i/%ttt/}:00'";;
*www1) if [[ "${i/%www1/}" = NULL ]]; then
out="$out,${i/%www1/}"
elif [[ -n "${i/%www1/}" ]]; then
out="$out,\$\$${i/%www1/}\$\$"
else until [[ -n "${var2}" ]]; do
var2="$(zenity --forms --title="invoice number field in table work" --text "Add a invoice number" --separator="," \
--add-entry="WARNING! You either forgot to enter a invoice number. Please enter a invoice number or NULL: ")"
if [[ "${var2}" = NULL ]]; then
out="$out,${var2}"
else
out="$out,\$\$${var2}\$\$"
fi
done
fi
;;
*www2) if [[ "${i/%www2/}" = NULL ]]; then
out="$out,${i/%www2/}"
elif [[ -n "${i/%www2/}" ]]; then
out="$out,\$\$${i/%www2/}\$\$"
else
until [[ -n "${var2}" ]]; do
var2="$(zenityi --forms --title="note field in table work" --text "Add a note" --separator="," \
--add-entry="WARNING! You either forgot to enter a note. Please enter a note or NULL: ")"
if [[ "${var2}" = NULL ]]; then
out="$out,${var2}"
else
out="$out,\$\$${var2}\$\$"
fi
done
fi
;;
*) out="$out,'${i}:00'";;
esac;
done
echo "${out:1}"
let a++
done
Simplified script:
#!/bin/bash
work_number="$(zenity --entry --text "ENTER number of work/job entries:" --entry-text "1")"
a=1
until
[[ $work_number -lt $a ]]
do
input="$(zenity --forms --title="table work" --text="Add a new job" --separator="," \
--add-entry="ENTER a: " \
--add-entry="ENTER invoice reference field: " \
--add-entry="ENTER b: ")"
input="$( echo "$input" | awk 'BEGIN { FS="," } { print $1 "," $2"www1" "," $3 ; }' )"
IFS=, read -ra myarray <<<"$input"
out=""
for i in "${myarray[@]}"; do
case "$i" in
*www1) if [[ "${i/%www1/}" = NULL ]]; then
out="$out,${i/%www1/}"
elif [[ -n "${i/%www1/}" ]]; then
out="$out,\$\$${i/%www1/}\$\$"
else until [[ -n "${var2}" ]]; do
var2="$(zenity --forms --title="invoice number field in table work" --text "Add a invoice number" --separator="," \
--add-entry="WARNING! You either forgot to enter a invoice number. Please enter a invoice number or NULL: ")"
if [[ "${var2}" = NULL ]]; then
out="${var2}"
else
out="\$\$${var2}\$\$"
fi
done
fi
;;
esac
done
out="${out#,}"
printf 'out=%s\n' "$out"
echo "$out"
let a++
done
Explanation
You're reusing the var2 variable without unsetting it (unset var2) or assigning an empty string to it (var2=''). Therefore until [[ -n "${var2}" ]]; do …; done uses some old non-empty value and the code in place of … is never executed.
In the simplified script var2 is still unset when you first get to until [[ -n "${var2}" ]]; do. This is the difference.
Each time you write until [[ -n "${var2}" ]]; do ask yourself if the current value of the variable (from the previous loop or so) should matter. If it shouldn't matter then make it not matter: unset the variable just before until.
An alternative is to organize your code in functions. In a function in Bash you can define local variables. Local var2 variable would have nothing to do with var2 (if any) in the main script or with var2 in another invocation of this or another function. See help local for details. E.g. if you create a function validate_invoice_number and define local var2 in it, then you will be able to use until [[ -n "${var2}" ]]; do in the function without any risk that some other (old) var2 interferes.
Example
The following piece of code is a flawed attempt to get two random numbers from a range from 0 to 9999. In Bash $RANDOM expands to a random integer from a range from 0 to 32767 We will keep querying Bash for random numbers until (by chance) we get one that meets our expectation. This is similar to your approach where you query the user. It's not the fastest method to get a random integer from the desired range, but in this case it's not fundamentally flawed either. The flaw is in reusing var2, like in your code. Diagnostic messages to stderr are here to help you understand what happens.
#!/bin/bash
for i in 1 2; do
echo "Loop $i starts. var2 is ${var2:-empty or unset}." >&2
until [ "$var2" -lt 10000 ] 2>/dev/null; do
echo "Trying new random number." >&2
var2="$RANDOM"
done
echo "Expectation met. Printing the result." >&2
echo "$var2"
echo "Loop $i ends. var2 is ${var2:-empty or unset}." >&2
done
Run the code and you will see the second loop does not obtain a new random number at all. Now let's try with unset:
#!/bin/bash
for i in 1 2; do
echo "Loop $i starts. var2 is ${var2:-empty or unset}." >&2
unset var2
echo "Loop $i continues. var2 is ${var2:-empty or unset}." >&2
until [ "$var2" -lt 10000 ] 2>/dev/null; do
echo "Trying new random number." >&2
var2="$RANDOM"
done
echo "Expectation met. Printing the result." >&2
echo "$var2"
echo "Loop $i ends. var2 is ${var2:-empty or unset}." >&2
done
Another approach is to use local var2 in a function:
#!/bin/bash
gimme_random () {
local var2
echo "Function starts. var2 inside is ${var2:-empty or unset}." >&2
until [ "$var2" -lt 10000 ] 2>/dev/null; do
echo "Trying new random number." >&2
var2="$RANDOM"
done
echo "Expectation met. Printing the result." >&2
echo "$var2"
echo "Function ends. var2 inside is ${var2:-empty or unset}." >&2
}
for i in 1 2; do
echo "Loop $i starts. var2 is ${var2:-empty or unset}." >&2
gimme_random
echo "Loop $i ends. var2 is ${var2:-empty or unset}." >&2
done
This works as expected. The variable inside the function has no connection to the variable outside of the function. When the function is run again, the variable in the new instance is local to the instance.
Try it without local var2 and it will behave like the first (flawed) snippet. In this case var2 outside of and inside the function (both instances) is the same var2.
Also note if you run the snippets by just pasting them sequentially in a single shell then var2 (unless local in the function) will remain from one snippet to the other. This will even emphasize the problem.