Standardin

Standardin is an informal term sometimes used to refer to the standard input stream of a program, which is more commonly called stdin. In formal programming terminology, the stream is stdin, short for standard input, and it is one of the three primary standard streams alongside stdout (standard output) and stderr (standard error). The label standardin appears mainly as a descriptive alias or a spelling variation in informal writing, code comments, or documentation errors, rather than as an official name in language specifications.

The concept of standard input originates in early operating systems and the C standard library, where each process has access to three pre-defined streams. In POSIX-compliant systems, stdin is file descriptor 0, stdout is 1, and stderr is 2. Programs read from stdin to obtain user input or data piped from other processes. Other languages expose similar facilities with different interfaces: C uses FILE* pointers with stdin as the input stream; Python uses input() or sys.stdin for reading from the standard input; Java provides System.in as an InputStream; and many shell environments use the standard input as the default source for commands unless redirected.

Usage examples vary by language but share the core idea: data is fed into a program through the standard input stream and consumed by the program logic. Input can be entered interactively by a user, redirected from a file, or supplied by the output of another program via piping. While standardin can appear in documentation or discussion as a shorthand, it is not a formal term and should be avoided in precise technical writing in favor of stdin.

See also: standard input, stdin, standard output, standard error, POSIX, file descriptor 0.