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- EVAL(1) MS-DOS auxiliary utilities EVAL(1)
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- NAME
- eval - evaluate a command after wildcard expansion, command
- and variable substitution
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- SYNOPSIS
- eval command [argument ... ]
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- DESCRIPTION
- eval is a utility to execute any given command, after
- performing wildcard expansion, command substitution and
- variable substitution on the arguments before running the
- command. The command line is iteratively scanned for
- command substitutions in backquotes (`...`) and environment
- variables (%var), and the resulting text used as the
- argument list for the first argument (the command to be
- run). Command substitutions are usually performed by loading
- a shell, which allows for batch files, shell aliases and
- pipelines in addition to executable programs. If the first
- character of the command is '@', the command is exec'ed
- directly (much faster than loading a shell, but only works
- with exe and com files) The magic characters '%','`', and
- '@' are set by #defines in comsub.h so you can change them
- if you don't like them.
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- When substituting the output of commands, newlines are
- replaced by spaces. Arguments may need to be quoted in order
- that eval will see the % or `...` characters, depending on
- which shell you use. The 4DOS shell in particular needs to
- have backquotes protected by double quotes.
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- DIAGNOSTICS
- Diagnostics are printed for the following errors:
- - out of memory
- - command substitution failed (command not found, or line too long)
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- EXAMPLES
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- SEE ALSO
- eval, incr, decr, expr
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- BUGS
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- AUTHOR
- Richard Brittain (richard@calvin.ee.cornell.edu)
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