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Table of Contents
Standard Streams
Standard streams are preconnected input and output communication channels between a computer program and its environment when it begins execution.
The three input/output connections are called stdin (standard input), stdout (standard output) and stderr (standard error).
When a command is executed via an interactive shell, the streams are typically connected to the text terminal on which the shell is running, but can be changed with redirection or a pipeline.
Stdin
Standard input is a stream from which a program reads its input data. The program requests data transfers by use of the read operation.
Unless redirected, standard input is inherited from the parent process. In the case of an interactive shell, that is usually associated with the keyboard.
For processes that use a file as input, that file data may be passed (or piped) in through the stdin channel.
Input via Stdin
Piping an input file myVolumes.csv via stdin to TMSS10Sync.
TMSS10Sync -S user:-password@serveraddress < myVolumes.csv
Stdout
Standard output is a stream to which a program writes its output data.
Unless redirected, standard output is inherited from the parent process.
Output Via Stdout
Redirecting stdout from TMSS10Sync to file sync_stdout.txt
TMSS10Sync -S user:-password@serveraddress < myVolumes.csv > sync_stdout.txt
Stderr
Standard error is another output stream typically used by programs to output error messages or diagnostics. It is a stream independent of standard output and can be redirected separately.