There are two handy tools that generate random passwords from the command line in Ubuntu (and other distros of course). It’s more secure to use passwords from these tools instead of online password generators.
First of which is apg and the second – which is my favorite – is pwgen
Sample output of apg:
apg Please enter some random data (only first 16 are significant) (eg. your old password):> Vefic7OjTyct (Vef-ic-SEVEN-Oj-Tyct) BudDelorkal7 (Bud-Del-ork-al-SEVEN) pedAfBuir1 (ped-Af-Bu-ir-ONE) AwdaftImoat9 (Awd-aft-Im-oat-NINE) EkWedivJaw1 (Ek-Wed-iv-Jaw-ONE) nojIvetad0 (noj-Iv-et-ad-ZERO)
Sample output from pwgen:
pwgen Peej5Roo ahW7zahw pheiz6Ea aeP4jogh eaX7ILoh we6Oohu5 tek3Neik KaHae7wo Shu4neil Iol8aeXo ahwu4Aef ca9asiRo AhNg6Chi iez6Eish Un4juoha neeY5phu jut2CohY aed4eeNg eiC0joh8 AhvaiD8v beWae2im Du6tahV8 baes0Qua Queece5A Pegh5the zaeth6Ie ieshieC7 Tu3EeJ2e ochai0De paP6Ahxe Ahta9mai Paiv7eez phae7Ohb xohJ6voo IuhaeM2e quaiG8th Eiw3hiev kao4Eezi cie8haD7 Oyui0Iev raey9Gie gi1loChe IPhe7bai Uju4ap4n ohsiez0S aiQu6yae zah2ooCh GeiC6ief ieShioZ7 ee1Caung aDai4eko Aixion0J Aeca1woo Aik4rie1 eix6ahNg Uah4oovi Ahpu6aet Nai0zeem lahSiet2 Omao8ohg Ahde3eis beesh9aG aeth8Ooh eBaen6ah Yai6eiph Tho2phaa shoh0aeR FoeB2xuZ vaiju6Ao aomien3J aiFai2qu iesh1aeB iz2quaiK kuhahV8o Visap6uy hai2ohHo quie5Dah Ook0yair Giesh5fa Po4pho2z qui3eaDe ehaiZu1A Quishah3 ohhie5iK in2OoLah baTah6li Zaiwae7r aeph3Xoh TeesooT9 aiLuph1A leufoh9A eeR2toos ugohx4Th Eekiig2h siemu4Oo GeegaTh0 Cahieg9h xapahDo4 Tii5shiR Otaefae2 eel1Aek2 chahGoo2 Ginoop6j zeiS2ohc Uchee0po Heeh7ieW NiDa8fo9 johgi5Oo sho1gu2A pej6cooW EetuJ6Ee ahTo4hav Geede9gi Sae9liet bo5Noo7r Eigai6uw aip3Paey Omoopho0 uFee9Aic eel3OY5S Hoo9dah0 Ahyoh4th ohg9ai0E Oowae6ru Gah3meeX wi4theiF phuo0ieV oaSh4eim Iexeo5oa chus5Tei eiQuoh7w oov2CeeC shie2Iap aehee7Oh IeKoh6ee Yech5Bie YoiGhoh2 Iekiev4e Eeph0boh aiNg4ais cahS9ohd ra2iPah5 chiep0Ah ieTha1Me daecoY5a ooFoh8ee iivo6oaP UvuSh8Oo US2da9Ie iG2exiru laW6eith biu0Weim IN6uquei ahgeic4B aif3Cili Iez1Yohk Raeg7aiz oo2Eixoo jel2ao1A bo0Shae5
You could of course generate much stronger passwords using additional parameters, just use man apg or man pwgen.
Enjoy!
Sources:
Just Some Techie Notes! 