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
Canned water under the United States Civil Defense program. Approximately twelve million cans were deployed, and could hold water for more than ten years. Later, some manufacturers started to use Nitrogen flush to remove air and bacteria from their cans to prolong shelf life to 30 years or longer, making the water suitable for long term storage. Canned water Canned water is drinking water, including spring water, carbonated water and mineral water, packaged in tin cans or beverage cans. In individual serving cans, it is less common alternative to bottled water. Canned water is often used where storage or distribution systems are