CompTIA Linux+ XK0-006 (V8) Practice Question

The correct command is sed -i 's/192.168.1.5/10.10.0.5/g' app.conf. Here is a breakdown of the command:

• sed is the stream editor command.
• The -i option stands for "in-place" and modifies the file directly.
• 's/old/new/g' is the substitution command.
  • s indicates the substitute command.
  • /192.168.1.5/ is the pattern to search for.
  • /10.10.0.5/ is the replacement string.
  • g is the global flag, which ensures all occurrences on each line are replaced, not just the first one. The command sed 's/192.168.1.5/10.10.0.5/g' app.conf is incorrect because it lacks the -i flag; it will only print the modified text to standard output and will not save the changes to the file. The command sed 's/192.168.1.5/10.10.0.5/g' app.conf > app.conf is incorrect and dangerous. The shell processes the redirection > by truncating the output file (app.conf) before the sed command runs. This results in sed reading an empty file and the original content being lost. The command sed -i 's/192.168.1.5/10.10.0.5/' app.conf is incorrect because it is missing the global g flag. It would only replace the first occurrence of the IP address on any given line.