How to search and extract string from command output?

Using sed

$ command | sed -n 's/.*text4://p'
 "lkpird sdfd"

-n tells sed not to print unless we explicitly ask it to. s/.*text4:// tells sed to remove any text from the beginning of the line to the final occurrence of text4:. If such a line is found, then the p tells sed to print it.

Using grep -P

$ command | grep -oP '(?<=text4:).*' 
 "lkpird sdfd"

-o tells grep to print only the matching part. (?<=text4:).* matches any text that follows text4: but does not include the text4:.

The -P option requires GNU grep. Thus, it will not work with busybox's builtin grep, nor with the default grep on BSD/Mac OSX systems.

Using awk

The original grep-awk solution can be simplified:

$ command | awk -F': ' '/text4: /{print $2}'
"lkpird sdfd"

Using awk (alternate)

$ command | awk '/text4:/{sub(/.*text4:/, ""); print}'
 "lkpird sdfd"

/text4:/ selects lines that contain text4:. sub(/.*text4:/, "") tells awk to remove all text from the beginning of the line to the last occurrence of text4: on the line. print tells awk to print those lines.

With grep and its PCRE support and \K notify.

command |grep -Po 'text4: \K.*'