如何使用sed查找并替换为特殊字符？

Question

I want to replace the ip '100.45.9.147' with $(cat apiServer.txt) . A non inplace update works but when i try to use sed's in-place update i get error :-

$ sed "s/'100.45.9.147'/\\$(cat apiServer.txt)/g" checkNTP.sh

echo -e "\n"
apiServer=$(cat apiServer.txt)
usertoken=$(cat tokenfile.txt)
curl -k  -H "Authorization: Bearer ${usertoken}" -H 'Content-Type: application/json' "https://${apiServer}/configapi/v1/SystemSettingsNTP"

echo -e "\n\n"

$ sed -i "s/'100.45.9.147'/\\$(cat apiServer.txt)/g" checkNTP.sh

sed: 1: "checkNTP.sh": command c expects \ followed by text

Here is the content of checkNTP.sh

echo -e "\n"
apiServer='100.45.9.147'
usertoken=$(cat tokenfile.txt)
curl -k  -H "Authorization: Bearer ${usertoken}" -H 'Content-Type: application/json' "https://${apiServer}/configapi/SystemSettingsNTP"

echo -e "\n\n"

Answer 1

使用下面的-i ''开关解决了这种情况：

sed -i '' "s/'10.45.9.147'/\\\\$\\\\(cat apiServer.txt\\\\)/g" fileName.txt

Answer 2

This might work for you (GNU sed):

sed 's/'\''100\.45\.9\.147'\''/$(cat apiServer.txt)/' file

Single quotes are best poked through quoted from the shell, this allows all other characters other than metacharacters to represent themselves and the metacharacters can be quoted as normal eg . must be quoted \\. otherwise it just represent a single character.

If you want a shell variable to replace text again poke a hole into the shell and surround the variable double quotes so as to allow for possible white space. Also remember that should the variable contain metacharacters these should be quoted beforehand otherwise the substitution command might cause a sed syntax error. This usually happens when the variable has characters in it that clash with the substitution delimiters ie normally /