Redirection (computing)

<p>In <a href="/facts/Computing/Kghtm9fX">computing</a>, redirection is a form of <a href="/facts/Interprocess_communication/cIQYyT6y">interprocess communication</a>, and is a function common to most <a href="/facts/Command-line_interpreter/R9JpGmXQ">command-line interpreters</a>, including the various <a href="/facts/Unix_shell/2G4T2Fb9">Unix shells</a> that can redirect <a href="/facts/Standard_streams/r92M7Wd4">standard streams</a> to user-specified locations. The concept of redirection is quite old, dating back to the earliest operating systems (OS). A discussion of the design goals for redirection can be found already in the 1971 description of the <a href="/facts/Input-output/WQTE8Jas">input-output</a> subsystem of the <a href="/facts/Multics/y7A5peyu">Multics</a> OS. However, prior to the introduction of <a href="/facts/UNIX/0pNL2seI">UNIX</a> OS with its "<a href="/facts/Pipeline_(Unix)/EIhovuT2">pipes</a>", redirection in operating systems was hard or even impossible to do.
</p><p>In <a href="/facts/Unix-like/YAKrAxzd">Unix-like</a> operating systems, programs do redirection with the <a href="/facts/Dup2/9zYeHEpF">dup2</a>(2) <a href="/facts/System_call/NW44AFJr">system call</a>, or its less-flexible but higher-level <a href="/facts/Standard_streams/r92M7Wd4">stdio</a> analogues, <a href="/facts/Freopen/m5n82Fqz">freopen</a>(3) and popen(3).
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Redirection (computing) open-in-new

Redirection (computing)