Shell Programming and Scripting

sed -e ':L1' -e N -e '$!bL1' -e "s/.*/'&'/;s/\n/','/g" file

sed -e '1h;1!H;$!d;g' -e "s/.*/'&'/;s/\n/','/g" file

sed 's/^/'\''/;s/$/'\''/;1h;1!H;$!d;x;s/\n/,/g' file

sed "s/.*/'&'/" file | paste -sd, -

var=$(sed "s/.*/'&'/" file | paste -sd, -)

# Change IFS to Support white space on lines
IFS=$'\n'
printf -v var "'%s', " $(< file)
IFS=$' \t\n'

# remove trailing ", "
var="${var%, }"

echo "$var"

ABC DEF
GHI
JKL
MNO

printf -v var "'%s', " $(< file)
echo "${var%, }"

var=$( while read L; do printf "%s'%s'" "$sep" "$L"; sep=", "; done < file )

var=$( awk '{printf "%s'\''%s'\''",sep,$0; sep=", "}' file )

rec=$(<file); var="'${rec//$'\n'/','}'"

rec=$(<fname); printf "%s\n" "'${rec//$'\n'/','}'"