This is a list of POSIX (Portable Operating System Interface) commands as specified by IEEE Std 1003.1-2024, which is part of the Single UNIX Specification (SUS). These commands can be found on Unix operating systems and most Unix-like operating systems.
This is not a comprehensive list of all utilities that existed in the various historic Unix and Unix-like systems, as it excludes utilities that were not mandated by the aforementioned standard.
| Name | Category | Status (Option code) | Description | First appeared |
|---|---|---|---|---|
| SCCS | (XSI) | Create and administer SCCS files | PWB UNIX | |
| Misc | Define or display aliases | |||
| Misc | Create and maintain library archives | Version 1 AT&T UNIX | ||
| Text processing | (FR) | Interpret carriage-control characters | System V | |
| Process management | Execute commands at a later time | Version 7 AT&T UNIX | ||
| Text processing | Pattern scanning and processing language | Version 7 AT&T UNIX | ||
| Filesystem | Return non-directory portion of a pathname; see also dirname | Version 7 AT&T UNIX | ||
| Process management | Schedule commands to be executed in a batch queue | |||
| Misc | Arbitrary-precision arithmetic language | Version 6 AT&T UNIX | ||
| Process management | (UP) | Run jobs in the background | ||
| / | C programming | (CD) | Compile standard C programs | IEEE Std 1003.1-2024 |
| Misc | (XSI) | Print a calendar | Version 5 AT&T UNIX | |
| Filesystem | Concatenate and print files | PDP-7 UNIX | ||
| Filesystem | Change the working directory | Version 6 AT&T UNIX | ||
| C programming | (XSI) | Generate a C-language call graph | System V | |
| Filesystem | Change the file group ownership | PWB UNIX | ||
| Filesystem | Change the file modes/attributes/permissions | PDP-7 UNIX | ||
| Filesystem | Change the file ownership | PDP-7 UNIX | ||
| Filesystem | Write file checksums and sizes | 4.4BSD | ||
| Filesystem | Compare two files; see also diff | Version 1 AT&T UNIX | ||
| Text processing | Select or reject lines common to two files | Version 4 AT&T UNIX | ||
| Shell programming | Execute a simple command | |||
| Filesystem | (XSI) | Compress data | 4.3BSD | |
| Filesystem | Copy files | PDP-7 UNIX | ||
| Misc | Schedule periodic background work | System V | ||
| Text processing | Split files based on context | PWB UNIX | ||
| C programming | (SD) | Create a tags file | 3BSD | |
| Text processing | Cut out selected fields of each line of a file | System III | ||
| C programming | (XSI) | Generate a C-language program cross-reference table | System V | |
| Misc | Display the date and time | Version 1 AT&T UNIX | ||
| Filesystem | Convert and copy a file | Version 5 AT&T UNIX | ||
| SCCS | (XSI) | Make a delta (change) to an SCCS file | PWB UNIX | |
| Filesystem | Report free disk space | Version 1 AT&T UNIX | ||
| Text processing | Compare two files; see also cmp | Version 5 AT&T UNIX | ||
| Filesystem | Return the directory portion of a pathname; see also basename | System III | ||
| Filesystem | Estimate file space usage | Version 1 AT&T UNIX | ||
| Shell programming | Write arguments to standard output | Version 2 AT&T UNIX | ||
| Text processing | The standard text editor | PDP-7 UNIX | ||
| Misc | Set the environment for command invocation | System III | ||
| Text processing | (UP) | Text editor | 1BSD | |
| Text processing | Convert tabs to spaces | 3BSD | ||
| Shell programming | Evaluate arguments as an expression | Version 7 AT&T UNIX | ||
| Shell programming | Return false value | Version 7 AT&T UNIX | ||
| Misc | (UP) | Process the command history list | ||
| Process management | (UP) | Run jobs in the foreground | ||
| Filesystem | Determine file type | Version 4 AT&T UNIX | ||
| Filesystem | Find files | Version 1 AT&T UNIX | ||
| Text processing | Filter for folding lines | 1BSD | ||
| Process management | (XSI) | List process IDs of all processes that have one or more files open | System V | |
| Misc | Generate a formatted message catalog | |||
| SCCS | (XSI) | Get a version of an SCCS file | PWB UNIX | |
| Misc | Get configuration values | |||
| Shell programming | Parse utility options | |||
| Misc | Retrieve text string from messages object | |||
| Misc | Search text for a pattern | Version 4 AT&T UNIX | ||
| Misc | Hash database access method | |||
| Text processing | Copy the first part of files | PWB UNIX | ||
| Text processing | Codeset conversion | HP-UX | ||
| Misc | Return user identity | System V | ||
| Misc | (XSI) | Remove a message queue, semaphore set, or shared memory segment identifier | System V | |
| Misc | (XSI) | Report interprocess communication facilities status | System V | |
| Process management | (UP) | Display status of jobs in the current session | ||
| Text processing | Merges two sorted text files based on the presence of a common field | Version 7 AT&T UNIX | ||
| Process management | Terminate or signal processes | Version 4 AT&T UNIX | ||
| C programming | (CD) | Generate programs for lexical tasks | Version 7 AT&T UNIX | |
| Filesystem | (XSI) | Create a hard link to a file | Version 1 AT&T UNIX | |
| Filesystem | Link files | Version 1 AT&T UNIX | ||
| Misc | Get locale-specific information | |||
| Misc | Define locale environment | |||
| Shell programming | Log messages | 4.3BSD | ||
| Misc | Return the user's login name | 4.4BSD | ||
| Text processing | Send files to a printer | System V | ||
| Filesystem | List directory contents | Version 1 AT&T UNIX | ||
| Misc | Macro processor | PWB UNIX | ||
| Misc | Process messages | Version 1 AT&T UNIX | ||
| Programming | (SD) | Maintain, update, and regenerate groups of programs | PWB UNIX | |
| Misc | Display system documentation | Version 2 AT&T UNIX | ||
| Misc | Permit or deny messages | Version 1 AT&T UNIX | ||
| Filesystem | Make directories | Version 1 AT&T UNIX | ||
| Filesystem | Make FIFO special files | 4.4BSD | ||
| Text processing | (UP) | Display files on a page-by-page basis | 3BSD | |
| Misc | Create messages objects from messages object files | |||
| Filesystem | Move or rename files | Version 1 AT&T UNIX | ||
| Misc | Change to a new group | Version 6 AT&T UNIX | ||
| Misc | Retrieve text string from messages object with plural form | |||
| Process management | Invoke a utility with an altered nice value | Version 4 AT&T UNIX | ||
| Text processing | (XSI) | Line numbering filter | System III | |
| C programming | (SD, XSI) | Write the name list of an object file | Version 1 AT&T UNIX | |
| Process management | Invoke a utility immune to hangups | Version 4 AT&T UNIX | ||
| Misc | Dump files in various formats | Version 1 AT&T UNIX | ||
| Text processing | Merge corresponding or subsequent lines of files | Version 32V AT&T UNIX | ||
| Text processing | Apply changes to files | 4.3BSD | ||
| Filesystem | Check pathnames | |||
| Misc | Portable archive interchange | 4.4BSD | ||
| Text processing | Paginate or columnate files for printing | Version 1 AT&T UNIX | ||
| Shell programming | Write formatted output | 4.3BSD-Reno | ||
| SCCS | (XSI) | Print an SCCS file | PWB UNIX | |
| Process management | Report process status | Version 4 AT&T UNIX | ||
| Filesystem | Print working directory | Version 5 AT&T UNIX | ||
| Shell programming | Read a line from standard input | |||
| Filesystem | Print destination of a symbolic link | |||
| Filesystem | Resolve a symbolic link | |||
| Process management | Set nice values of running processes | 4BSD | ||
| Filesystem | Remove directory entries | Version 1 AT&T UNIX | ||
| SCCS | (XSI) | Remove a delta from an SCCS file | PWB UNIX | |
| Filesystem | Remove directories, if they are empty. | Version 1 AT&T UNIX | ||
| SCCS | (XSI) | Print current SCCS file-editing activity | System III | |
| SCCS | (XSI) | Front end for the SCCS subsystem | 4.3BSD | |
| Text processing | Stream editor | Version 7 AT&T UNIX | ||
| Shell programming | Shell, the standard command language interpreter | Version 7 AT&T UNIX (in earlier versions, sh was either the Thompson shell or the PWB shell) | ||
| Shell programming | Suspend execution for an interval | Version 4 AT&T UNIX | ||
| Text processing | Sort, merge, or sequence check text files | Version 1 AT&T UNIX | ||
| Misc | Split files into pieces | Version 3 AT&T UNIX | ||
| C programming | Find printable strings in files | 2BSD | ||
| C programming | (SD) | Remove unnecessary information from executable files | Version 1 AT&T UNIX | |
| Misc | Set the options for a terminal | Version 2 AT&T UNIX | ||
| Misc | Set terminal tabs | PWB UNIX | ||
| Text processing | Copy the last part of a file | PWB UNIX | ||
| Misc | (UP) | Talk to another user | 4.2BSD | |
| Shell programming | Duplicate the standard output | Version 5 AT&T UNIX | ||
| Shell programming | Evaluate expression | Version 7 AT&T UNIX | ||
| Process management | Retrieve and format time and date | Version 3 AT&T UNIX | ||
| Process management | Run command with a time limit | Version 3 AT&T UNIX | ||
| Filesystem | Change file access and modification times | Version 7 AT&T UNIX | ||
| Misc | Change terminal characteristics | System V | ||
| Text processing | Translate characters | Version 4 AT&T UNIX | ||
| Shell programming | Return true value | Version 7 AT&T UNIX | ||
| Text processing | Topological sort | Version 7 AT&T UNIX | ||
| Misc | Return user's terminal name | Version 1 AT&T UNIX | ||
| Misc | (XSI) | Displays how a name would be interpreted if used as a command | ||
| Misc | (XSI) | Set or report file size limit | ||
| Misc | Get or set the file mode creation mask | System III | ||
| Misc | Remove alias definitions | |||
| Misc | Return system name | PWB UNIX | ||
| Misc | (XSI) | Expand compressed data | 4.3BSD | |
| Text processing | Convert spaces to tabs | 3BSD | ||
| SCCS | (XSI) | Undo a previous get of an SCCS file | System III | |
| Text processing | Report or filter out repeated lines in a file | Version 3 AT&T UNIX | ||
| Filesystem | (XSI) | Call the unlink function | Version 1 AT&T UNIX | |
| Network | (UU) | System-to-system copy | Version 7 AT&T UNIX | |
| Network | Decode a binary file | 4BSD | ||
| Network | Encode a binary file | 4BSD | ||
| Network | (UU) | uucp status inquiry and job control | System III | |
| Process management | (UU) | Remote command execution | Version 7 AT&T UNIX | |
| SCCS | (XSI) | Validate SCCS files | System III | |
| Text processing | (UP) | Screen-oriented (visual) display editor | 1BSD | |
| Process management | Await process completion | Version 4 AT&T UNIX | ||
| Text processing | Line, word and byte or character count | Version 1 AT&T UNIX | ||
| SCCS | (XSI) | Identify SCCS files | PWB UNIX | |
| System administration | (XSI) | Display who is on the system | Version 1 AT&T UNIX | |
| Misc | Write to another user's terminal | Version 1 AT&T UNIX | ||
| Shell programming | Construct argument lists and invoke utility | PWB UNIX | ||
| C programming | (CD) | Extract gettext calls from C source code strings | IEEE Std 1003.1-2024 | |
| C programming | (CD) | Yet another compiler compiler | PWB UNIX | |
| Text processing | (XSI) | Expand and concatenate data | 4.3BSD | |