'Find' exercises in lez4
Grep exercises added in lesson4
First exercises on text manipulation
Merge branch 'lezione3' into lezione4 (solutions)
Solutions for lesson4
Minor changes in lesson 4 part 3 - text
Minor changes in lesson 3 - part 3
Merge branch 'lezione3' into lezione4(aliases and ticks)
Merge branch 'lezione3' into lezione4(tar & co)
New exercises in lesson 4 part 3
Merge branch 'lezione3' into lezione4 (intro)
New exercises (grep -v and sed)
Merge branch 'lezione4'