select construct allows the easy generation of
menus. It has almost the same syntax as the
Syntax select name [in words ...]; do commands; done
The list of words following
in is expanded, generating a list
of items. The set of expanded words is printed on the standard error output
stream, each preceded by a number.
If the 'in words' is omitted, the positional parameters are printed, as if 'in "$@"' had been specifed. The
prompt is then displayed and a line is read from the standard input. If the
line consists of a number corresponding to one of the displayed words, then
the value of name is set to that word. If the line is empty, the
words and prompt are displayed again. If
EOF is read, the
command completes. Any other value read causes name to be set to
null. The line read is saved in the variable
The commands are executed after each selection until a
return command is executed, at which point the
Here is an example that allows the user to pick a filename from the current directory, and displays the name and index of the file selected.
select fname in *; do echo you picked $fname \($REPLY\) break; done
(( expression ))
If the value of the expression is non-zero, the return status is 0; otherwise the return status is 1. This is exactly equivalent to
"The truly successful businessman is essentially a dissenter, a rebel who is seldom if ever satisfied with the status quo" ~ J. Paul Getty
read - read a line from standard input.
for - Expand words, and execute commands.
if - Conditionally perform a command.
until - Execute commands (until error).
Equivalent Windows command: CHOICE - Accept keyboard input to a batch file.