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
Environmental issues in Brazil a landfill in Nova Iguaçu (Rio de Janeiro area), methane is being collected and converted into electricity. This process is expected to eliminate 2.5 million tons of carbon dioxide emissions by 2012. According to data from the Brazilian Association of Public Cleaning and Special Waste Companies including sewage, Brazil is a leader in aluminum can recycling without government intervention with ten cans being recycled every year. In 2007, more than 96% of cans available in the market were recycled. This leadership comes from informal waste scavengers that make their living by collecting aluminum cans. However, recycling in general in Brazil