\b0 prints out the values of the variables in the environment. If a name is specified, only its value is printed. If a name is specified and it is not defined in the environment, printenv returns exit status 1, else it returns status 0.
CommandArgument
{\rtf0\ansi{\fonttbl\f0\fmodern Courier;}
\margl40
\margr40
\pard\tx520\tx1060\tx1600\tx2120\tx2660\tx3200\tx3720\tx4260\tx4800\tx5320\f0\b0\i0\ulnone\fs24\fc0\cf0 The name of the environment variable to print
\b0 makes a typescript of everything printed on your terminal. The typescript is written to file, or appended to file if the -a option is given. It can be sent to the line printer later with lpr. If no file name is given, the typescript is saved in the file typescript. The script ends when the forked shell exits. This program is useful when using a crt and a hard-copy record of the dialog is desired, as for a student handing in a program that was developed on a crt when hard-copy terminals are in short supply.
\pard\tx533\tx1067\tx1601\tx2135\tx2668\tx3202\tx3736\tx4270\tx4803\tx5337\f0\b0\i0\ulnone\fs24\fc0\cf0 Typescript is appended to a file if this option is given
{\rtf0\ansi{\fonttbl\f0\fmodern Courier;}
\margl40
\margr40
\pard\tx520\tx1060\tx1600\tx2120\tx2660\tx3200\tx3720\tx4260\tx4800\tx5320\f0\b0\i0\ulnone\fs24\fc0\cf0 The file to write the typescript to
(.txt)