> For the complete documentation index, see [llms.txt](https://woodrowpearson.gitbook.io/code-gists/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://woodrowpearson.gitbook.io/code-gists/bash/shell-commands-bash-reference-manual.md).

# Shell Commands (Bash Reference Manual)

A simple shell command such as `echo a b c` consists of the command itself followed by arguments, separated by spaces.

More complex shell commands are composed of simple commands arranged together in a variety of ways: in a pipeline in which the output of one command becomes the input of a second, in a loop or conditional construct, or in some other grouping. • [Simple Commands](/code-gists/bash/simple-commands-bash-reference-manual.md#Simple-Commands):  The most common type of command. • [Pipelines](/code-gists/bash/pipelines-bash-reference-manual.md#Pipelines):  Connecting the input and output of several commands. • [Lists](/code-gists/bash/lists-bash-reference-manual.md#Lists):  How to execute commands sequentially. • [Compound Commands](/code-gists/bash/compound-commands-bash-reference-manual.md#Compound-Commands):  Shell commands for control flow. • [Coprocesses](/code-gists/bash/coprocesses-bash-reference-manual.md#Coprocesses):  Two-way communication between commands. • [GNU Parallel](/code-gists/bash/gnu-parallel-bash-reference-manual.md#GNU-Parallel):  Running commands in parallel.