GNU CoreutilsThis manual documents version 5.93 of the GNU core utilities, including the standard programs for text and file manipulation.
Copyright © 1994, 1995, 1996, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".
- Introduction: Caveats, overview, and authors.
- Common options: Common options.
- Output of entire files: cat tac nl od
- Formatting file contents: fmt pr fold
- Output of parts of files: head tail split csplit
- Summarizing files: wc sum cksum md5sum sha1sum sha2
- Operating on sorted files: sort uniq comm ptx tsort
- Operating on fields within a line: cut paste join
- Operating on characters: tr expand unexpand
- Directory listing: ls dir vdir dircolors
- Basic operations: cp dd install mv rm shred
- Special file types: ln mkdir rmdir mkfifo mknod
- Changing file attributes: chgrp chmod chown touch
- Disk usage: df du stat sync
- Printing text: echo printf yes
- Conditions: false true test expr
- Redirection: tee
- File name manipulation: dirname basename pathchk
- Working context: pwd stty printenv tty
- User information: id logname whoami groups users who
- System context: date uname hostname
- Modified command invocation: chroot env nice nohup su
- Process control: kill
- Delaying: sleep
- Numeric operations: factor seq
- File permissions: Access modes.
- Date input formats: Specifying date strings.
- Opening the software toolbox: The software tools philosophy.
- GNU Free Documentation License: The license for this documentation.
- Index: General index.
--- The Detailed Node Listing ---
- Exit status: Indicating program success or failure.
- Backup options: Backup options
- Block size: Block size
- Target directory: Target directory
- Trailing slashes: Trailing slashes
- Traversing symlinks: Traversing symlinks to directories
- Treating / specially: Treating / specially
- Standards conformance: Standards conformance
Output of entire files
- cat invocation: Concatenate and write files.
- tac invocation: Concatenate and write files in reverse.
- nl invocation: Number lines and write files.
- od invocation: Write files in octal or other formats.
Formatting file contents
- fmt invocation: Reformat paragraph text.
- pr invocation: Paginate or columnate files for printing.
- fold invocation: Wrap input lines to fit in specified width.
Output of parts of files
- head invocation: Output the first part of files.
- tail invocation: Output the last part of files.
- split invocation: Split a file into fixed-size pieces.
- csplit invocation: Split a file into context-determined pieces.
- wc invocation: Print newline, word, and byte counts.
- sum invocation: Print checksum and block counts.
- cksum invocation: Print CRC checksum and byte counts.
- md5sum invocation: Print or check MD5 digests.
- sha1sum invocation: Print or check SHA-1 digests.
- sha2 utilities: Print or check SHA-2 digests.
Operating on sorted files
- sort invocation: Sort text files.
- uniq invocation: Uniquify files.
- comm invocation: Compare two sorted files line by line.
- ptx invocation: Produce a permuted index of file contents.
- tsort invocation: Topological sort.
ptx: Produce permuted indexes
- General options in ptx: Options which affect general program behavior.
- Charset selection in ptx: Underlying character set considerations.
- Input processing in ptx: Input fields, contexts, and keyword selection.
- Output formatting in ptx: Types of output format, and sizing the fields.
- Compatibility in ptx: The GNU extensions to
Operating on fields within a line
- cut invocation: Print selected parts of lines.
- paste invocation: Merge lines of files.
- join invocation: Join lines on a common field.
Operating on characters
- tr invocation: Translate, squeeze, and/or delete characters.
- expand invocation: Convert tabs to spaces.
- unexpand invocation: Convert spaces to tabs.
tr: Translate, squeeze, and/or delete characters
- Character sets: Specifying sets of characters.
- Translating: Changing one set of characters to another.
- Squeezing: Squeezing repeats and deleting.
- ls invocation: List directory contents
- dir invocation: Briefly list directory contents
- vdir invocation: Verbosely list directory contents
- dircolors invocation: Color setup for
ls: List directory contents
- Which files are listed: Which files are listed
- What information is listed: What information is listed
- Sorting the output: Sorting the output
- More details about version sort: More details about version sort
- General output formatting: General output formatting
- Formatting the file names: Formatting the file names
- cp invocation: Copy files and directories
- dd invocation: Convert and copy a file
- install invocation: Copy files and set attributes
- mv invocation: Move (rename) files
- rm invocation: Remove files or directories
- shred invocation: Remove files more securely
Special file types
- link invocation: Make a hard link via the link syscall
- ln invocation: Make links between files
- mkdir invocation: Make directories
- mkfifo invocation: Make FIFOs (named pipes)
- mknod invocation: Make block or character special files
- readlink invocation: Print the referent of a symbolic link
- rmdir invocation: Remove empty directories
- unlink invocation: Remove files via unlink syscall
Changing file attributes
- chown invocation: Change file owner and group
- chgrp invocation: Change group ownership
- chmod invocation: Change access permissions
- touch invocation: Change file timestamps
- df invocation: Report file system disk space usage
- du invocation: Estimate file space usage
- stat invocation: Report file or file system status
- sync invocation: Synchronize data on disk with memory
- echo invocation: Print a line of text
- printf invocation: Format and print data
- yes invocation: Print a string until interrupted
- false invocation: Do nothing, unsuccessfully
- true invocation: Do nothing, successfully
- test invocation: Check file types and compare values
- expr invocation: Evaluate expressions
test: Check file types and compare values
- File type tests: File type tests
- Access permission tests: Access permission tests
- File characteristic tests: File characteristic tests
- String tests: String tests
- Numeric tests: Numeric tests
expr: Evaluate expression
- String expressions: + : match substr index length
- Numeric expressions: + - * / %
- Relations for expr: | & < <= = == != >= >
- Examples of expr: Examples of using
- tee invocation: Redirect output to multiple files
File name manipulation
- basename invocation: Strip directory and suffix from a file name
- dirname invocation: Strip non-directory suffix from a file name
- pathchk invocation: Check file name portability
- pwd invocation: Print working directory
- stty invocation: Print or change terminal characteristics
- printenv invocation: Print all or some environment variables
- tty invocation: Print file name of terminal on standard input
stty: Print or change terminal characteristics
- Control: Control settings
- Input: Input settings
- Output: Output settings
- Local: Local settings
- Combination: Combination settings
- Characters: Special characters
- Special: Special settings
- id invocation: Print user identity
- logname invocation: Print current login name
- whoami invocation: Print effective user ID
- groups invocation: Print group names a user is in
- users invocation: Print login names of users currently logged in
- who invocation: Print who is currently logged in
- date invocation: Print or set system date and time
- uname invocation: Print system information
- hostname invocation: Print or set system name
- hostid invocation: Print numeric host identifier.
date: Print or set system date and time
- Time conversion specifiers: %[HIklMNpPrRsSTXzZ]
- Date conversion specifiers: %[aAbBcCdDeFgGhjmuUVwWxyY]
- Literal conversion specifiers: %[%nt]
- Padding and other flags: Pad with zeroes, spaces, etc.
- Setting the time: Changing the system clock.
- Options for date: Instead of the current time.
- Examples of date: Examples.
Modified command invocation
- chroot invocation: Run a command with a different root directory
- env invocation: Run a command in a modified environment
- nice invocation: Run a command with modified niceness
- nohup invocation: Run a command immune to hangups
- su invocation: Run a command with substitute user and group ID
- kill invocation: Sending a signal to processes.
- sleep invocation: Delay for a specified time
- factor invocation: Print prime factors
- seq invocation: Print numeric sequences
- Mode Structure: Structure of File Permissions
- Symbolic Modes: Mnemonic permissions representation
- Numeric Modes: Permissions as octal numbers
Date input formats
- General date syntax: Common rules.
- Calendar date items: 19 Dec 1994.
- Time of day items: 9:20pm.
- Time zone items: EST, PDT, GMT.
- Day of week items: Monday and others.
- Relative items in date strings: next tuesday, 2 years ago.
- Pure numbers in date strings: 19931219, 1440.
- Seconds since the Epoch: @1078100502.
- Specifying time zone rules: TZ="America/New_York", TZ="UTC0".
- Authors of get_date: Bellovin, Eggert, Salz, Berets, et al.
Opening the software toolbox
- Toolbox introduction: Toolbox introduction
- I/O redirection: I/O redirection
- The who command: The
- The cut command: The
- The sort command: The
- The uniq command: The
- Putting the tools together: Putting the tools together