STDERR is an abbreviation for "standard error" in computer programming and operating systems. It refers to a communication channel or file descriptor used to output error messages or diagnostics from a command-line interface (CLI) application or program.
In CLI environments, there are three standard I/O streams by default: STDIN, STDOUT, and STDERR. STDIN is used for input, STDOUT for normal output, and STDERR exclusively for error messages. Typically, STDOUT and STDERR are displayed on the terminal window.
STDERR plays a crucial role in debugging and troubleshooting programs. When an application encounters an error or exception during execution, it utilizes STDERR to provide informative error messages to the user or developer. These error messages help in identifying and resolving issues, such as incorrect inputs, improper syntax, or internal errors.
By separating error output from regular output, STDERR allows users to redirect or capture error messages separately. This flexibility enables programmers to filter and analyze error logs, handle errors differently, or redirect them to error tracking systems.
In command-line interfaces, STDERR is commonly represented as a numeric file descriptor, with 2 being the standard value for STDERR. For example, the command "2>error.log" redirects STDERR to the file named "error.log", capturing error messages for further analysis or review.
