True and false (commands) True and false (commands) In Unix-like operating systems, codice_1 and codice_2 are commands whose only function is to always return with a predetermined exit status. Programmers and scripts often use the exit status of a command to assess success (exit status zero) or failure (non-zero) of the command. The codice_1 and codice_2 commands represent the logical values of command success, because "true" returns 0, and "false" returns 1. The commands are usually employed in conditional statements and loops of shell scripts. For example, the following shell script repeats the "echo hello" loop until interrupted: while true do done The commands
Expiration date not exposed to freezing temperatures, or temperatures above 90 °F (32.2° C). If the cans look okay, they are safe to use. Discard cans that are dented, rusted, or swollen. High-acid canned foods (tomatoes, fruits) will keep their best quality for 12 to 18 months; low-acid canned foods (meats, vegetables) for 2 to 5 years". . "Sell by date" is a less ambiguous term for what is often referred to as an "expiration date". Most food is still edible after the expiration date. A product that has passed its shelf life might still be safe, but quality is no longer