XK0-006 System Management Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  sed -e 's/oldhost/newhost/' /etc/hosts

  Why it's wrong here

  Without the g flag, sed replaces only the first occurrence per line, leaving later 'oldhost' entries unchanged. It is tempting because the substitution syntax and file target are correct, but global replacement across every occurrence on each line requires the s/oldhost/newhost/g form.

• ✗

  sed -n 's/oldhost/newhost/gp' /etc/hosts

  Why it's wrong here

  The -n flag suppresses automatic printing, so only substituted lines print, and it never writes changes back to /etc/hosts. It is tempting because the g flag correctly targets every occurrence, which is right when printing matches rather than editing the file in place.

• ✗

  sed 's/oldhost/newhost/' /etc/hosts

  Why it's wrong here

  Omitting the g flag replaces only the first match per line, leaving later occurrences of oldhost untouched in /etc/hosts. It is tempting because the same syntax works for single-match substitutions, which is the correct choice when only one instance per line needs changing.

• ✓

  sed -i 's/oldhost/newhost/g' /etc/hosts

  Why this is correct

  The `-i` flag edits /etc/hosts in place, satisfying the requirement to replace content within that file directly. The `g` suffix applies the substitution to every occurrence per line, not merely the first, matching "all occurrences". Without `g`, only the initial match on each line would change.

Go deeper

Related to this question