find and replace using sed command - regex

Question

I want to find single quote ' between double quotes and replace it with (back slash single quote single quote) \' ' using sed command.
input = 'gender':"Men's",'colour':'Red','name':"Men's levi's"
output = 'gender':"Men\' 's",'colour':'Red','name':"Men\' 's levi\' 's"
I tried this where I can replace comma with pipe but when trying to replace single quote with \' ' it doesn't work:
sed 's/(\"[^"\'']\{1,\}),([^"\'']\{1,\}\")/\1 | \2/g' test.csv

Answer 1

Here is a way to do that using awk:
awk 'BEGIN{FS=OFS=","} {
for (i=1; i<=NF; i++)
if (split($i, a, / *: */) == 2 && a[2] ~ /^"/) {
gsub("\047", "\\\047 \047", a[2])
$i=a[1] ":" a[2]
}
} 1' file
'gender':"Men\' 's",'colour':'Red','name':"Men\' 's levi\' 's"

Answer 2

With GNU awk for multi-char RS and RT, all you need is:
$ awk -v RS='"[^"]+"' '{gsub(/\047/,"\\\047 \047",RT); ORS=RT} 1' file
'gender':"Men\' 's",'colour':'Red','name':"Men\' 's levi\' 's"

Answer 3

With sed you could do this:
sed -e ":a"
-e "s/'\([^\\\":]*\(\\.[^\\\":]*\)*\"\)/\\\\\f \f\1/"
-e "ta"
-e "s/\\\\\f \f/\\\' '/g" file
Linebreaks and indentations are for readability. The whole point is that you first match single quotes that are followed by a double quote (might not be immediately), replace it with a \\\f \f (\\ a literal backslash, \f form feed) do the same thing using a loop (t) then you replace previous replacement with your desired string. The main regex also takes care from escaped double quotation marks inside a double quoted string but it fails if you have colons : or commas , within it.
One-liner:
sed -e ":a" -e "s/'\([^\\\":]*\(\\.[^\\\":]*\)*\"\)/\\\\\f \f\1/" -e "ta" -e "s/\\\\\f \f/\\\' '/g" file