Tornado

Tornado 2.0
User’s Guide
Table 5-14
Shell Special Characters (Continued)
stty Setting Common Value Description
start CTRL+Q Resume output.
susp CTRL+Z Suspend the Tornado shell.
N/A ESC Toggle between input mode and edit mode.
This character is fixed; you cannot change it with stty.
-> copy < input > output
If the file to which standard output is redirected does not exist, it is created.
Ambiguity Between Redirection and C Operators
There is an ambiguity between redirection specifications and the relational
operators less than and greater than. The shell always assumes that an ambiguous
use of < or > specifies a redirection rather than a relational operation. Thus the
ambiguous input line:
-> x > y
writes the value of the variable x to the stream named y, rather than comparing the
value of variable x to the value of variable y. However, you can use a semicolon to
remove the ambiguity explicitly, because the shell requires that the redirection
specification be the last element on a line. Thus the following input lines are
unambiguous:
-> x; > y
-> x > y;
The first line prints the value of the variable x to the output stream y. The second
line prints on standard output the value of the expression “x greater than y.”
The Nature of Redirection
The redirection mechanism of the Tornado shell is fundamentally different from
that of the Windows command shell, although the syntax and terminology are
similar. In the Tornado shell, redirecting input or output affects only a command
executed from the shell. In particular, this redirection is not inherited by any tasks
started while output is redirected.
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