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- Filters:
UNIX "building block" utilities designed to work with each other
- A filter reads a file, else its standard input (stdin);
writes to its standard output (stdout)
- A pipe (written |) connects stdout of one process to
stdin of another process.
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Example: grep reads files and writes matching lines to
its stdout; lpr reads its stdin, then prints it:
% grep something file* | lpr
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Example: Same as above, but pr paginates output of
grep and adds page headers and numbers, passes its
results to lpr:
% grep something file* | pr | lpr
- Learn the UNIX utilities.
You can use them on the command line and in shell script files.
Also, then...
you may not need to write as many Perl (Python/Tcl/etc.) scripts!
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