# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/(\{|,)\"(?!slug).*?\"//g;t' <<< "[{\"id\":\"0\",\"title\":\"Testowy post Laravela\",\"subtitle\":\"\",\"author\":\"Marcin\",\"content\":\"Tekst nr 4\",\"slug\":\"testowy-post-laravela-4\",\"created_at\":\"2014-11-02 10:30:42\",\"updated_at\":\"2014-11-02 10:30:42\"},{\"id\":\"1\",\"title\":\"Testowy post Laravela\",\"subtitle\":\"\",\"author\":\"Marcin\",\"content\":\"Tekst nr 0\",\"slug\":\"testowy-post-laravela-0\",\"created_at\":\"2014-11-02 10:30:42\",\"updated_at\":\"2014-11-02 10:30:42\"},{\"id\":\"2\",\"title\":\"Testowy post Laravela\",\"subtitle\":\"It's a rocket!\",\"author\":\"Marcin\",\"content\":\"Tekst nr 1\",\"slug\":\"testowy-post-laravela-1\",\"created_at\":\"2014-11-02 10:30:42\",\"updated_at\":\"2014-11-02 10:30:42\"},{\"id\":\"3\",\"title\":\"Testowy post Laravela\",\"subtitle\":\"\",\"author\":\"Marcin\",\"content\":\"Tekst nr 2\",\"slug\":\"testowy-post-laravela-2\",\"created_at\":\"2014-11-02 10:30:42\",\"updated_at\":\"2014-11-02 10:30:42\"},{\"id\":\"19\",\"title\":\"Testowy post Laravela\",\"subtitle\":\"\",\"author\":\"Marcin\",\"content\":\"Tekst nr 3\",\"slug\":\"testowy-post-laravela-3\",\"created_at\":\"2014-11-02 10:30:42\",\"updated_at\":\"2014-11-02 10:30:42\"}]"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html