on operators as well. If the file argument to one of the primaries is of the form `/dev/fd/N', then file descriptor N is checked. If the file argument to one of the primaries is one of `/dev/stdin', `/dev/stdout', or `/dev/stderr', fi... True if shell option optname is enabled. The list of options appears in the description of the `-o' option to the set builtin (see section 4... The Set Builtin).
-z string
True if the length of string is zero.
-n string
string
True if the
his functionality as a command, but a combination of commands will make this work.
The stty command s... ssumption that echo is on. In some cases, echoing of characters is done at the local terminal (in whic... cannot prevent echoing passwords) and the result of the second command will be that every character t... at stty trick is used in which the original state of stty is stored before the stty change and restore
