redirectstdout

Redirectstdout refers to the process of directing the standard output stream (stdout) away from its default destination, typically the terminal, toward another destination such as a file, a network socket, or an in-memory buffer. The concept exists across operating systems and programming languages, and the exact mechanism varies by environment.

In Unix-like shells, stdout can be redirected using redirection operators. For example, command > file.txt sends stdout to file.txt, while command >> file.txt appends to the file. A common pattern is command 2>&1 to merge stdout and stderr so both streams go to the same destination. Programs can also be incorporated into pipelines or combined with utilities like tee to display and save output simultaneously.

In programming languages, stdout redirection is supported by language APIs or facilities. Python provides redirect_stdout as a context manager to temporarily swap sys.stdout with another file-like object. Java can redirect System.out by replacing the PrintStream via System.setOut. C and C++ can redirect stdout using freopen or by altering the standard library streams. Node.js can intercept or replace process.stdout.write, though this is less common in typical applications.

Use cases include logging, test isolation, suppressing noisy output, and capturing program output for analysis. Important considerations include ensuring the destination is writable, handling buffering and flushing, and restoring the original stdout afterwards to avoid side effects. In multi-threaded programs, outputs from different threads may interleave, which may require synchronization.

See also: standard streams, input/output redirection, piping. Note that the exact name redirectstdout may be used informally to describe this capability, but implementations and APIs vary by language and environment.