Change specific line in a file while transfering using SSH

Question

I'm deploying my project to production server using scp command. As part of the deployment process I upload to server the .htaccess file. Locally, the environment is set to DEVELOPMENT:

#Set environment
#[PRODUCTION, STAGING, TESTING, DEVELOPMENT] 

SetEnv KOHANA_ENV 'DEVELOPMENT'

However, when uploaded to server it needs to be changed to PRODUCTION. Is there any way I can accomplish that with ssh?

Answer 1

You can do it with a sed command and the -i flag to edit the file in place:

sed -i "s/SetEnv KOHANA_ENV 'DEVELOPMENT'/SetEnv KOHANA_ENV 'PRODUCTION'/g" /path/to/.htaccess

Via ssh I would look like this:

ssh user@host "sed -i \"s/SetEnv KOHANA_ENV 'DEVELOPMENT'/SetEnv KOHANA_ENV 'PRODUCTION'/g\" /path/to/.htaccess"

Working with sed to replace strings in files is quite simple:

sed -i 's/search_string/replace_string/g' file

Replaces all occurences of search_string with replace_string of the gives file. -i causes sed to edit the file in place, instead of writing to standard output (stdout).

If you only want the first occurence to be replace use this sed command:

sed -i '0,/search_string/s/search_string/replace_string/' file

For more information about sed use man sed.

Answer 2

You can directly write to the file locally as follows:

echo "#Set environment
#[PRODUCTION, STAGING, TESTING, DEVELOPMENT] 

SetEnv KOHANA_ENV 'PRODUCTION'" > /path/to/.htaccess

Remember to replace /path/to/ with the path to .htaccess and then copy the file using scp. This will replace the contents of the file.

Answer 3

If you want to convert just the 28th line, you can do:

sed '28s/DEVELOPMENT/PRODUCTION/' file

(combinable with -i option, of course)

If you want to avoid modifying a local file, you can do:

< /local/path/to/.htaccess sed '28s/DEVELOPMENT/PRODUCTION/' | ssh user@host "cat > /server/path/to/.htaccess"