eval (Command)
evalexpression1 [ ,expression2 …] [output=outspec]
This command evaluates each expression and displays the results in the message window.
The output of each expression is separated from the next by the value of the
$OFS variable and terminated by the value of the
$ORS variable. By default
$OFS is a single blank and
$ORS is a single newline character. The expressions may be printed to a file or pipe using the
output= specifier argument. Refer to
show aliases for a complete description of output option. Note that expressions are delimited by a comma. In this case,
outspec can be any of the following:
• The name of a file (this can be a complete path name). A right angle bracket (>) preceding the file name causes the result of the eval command to be appended to the end of the file.
• An asterisk (*) indicating the message window. If preceded by a right angle bracket (>*), the output is appended to the message window instead of replacing its contents. Additional predefined message windows msgwin2, msgwin3, or msgwin4 use the specifier output=*2, output=*3, or output=*4 respectively.
• A question mark (?) preceding the output file name. If the file name starts with a question mark, the file name is a variable name whose value is set to the output produced by the command. If the second character is a right angle bracket (>), the output is appended to the current value of the variable instead of replacing it.
• An exclamation point (!) preceding an output specifier. This suppresses the normal prompt to confirm overwriting an existing file.
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Use only whole numbers within eval commands; the eval command does not perform floating point arithmetic.
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Example
eval (3 + 4) * 5
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