Next: Introduction, Up: (dir) [Contents][Index]

GNU Coreutils

This manual documents version 9.5 of the GNU core utilities, including the standard programs for text and file manipulation.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 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”.

1 Introduction
2 Common options
- 2.1 Backup options
- 2.2 Block size
- 2.3 Signal specifications
- 2.4 chown, chgrp, chroot, id: Disambiguating user names and IDs
- 2.5 Sources of random data
- 2.6 Target directory
- 2.7 Trailing slashes
- 2.8 Traversing symlinks
- 2.9 Treating / specially
- 2.10 Special built-in utilities
- 2.11 Exit status
- 2.12 Floating point numbers
- 2.13 Standards conformance
- 2.14 coreutils: Multi-call program
3 Output of entire files
- 3.1 cat: Concatenate and write files
- 3.2 tac: Concatenate and write files in reverse
- 3.3 nl: Number lines and write files
- 3.4 od: Write files in octal or other formats
- 3.5 base32: Transform data into printable data
- 3.6 base64: Transform data into printable data
- 3.7 basenc: Transform data into printable data
4 Formatting file contents
- 4.1 fmt: Reformat paragraph text
- 4.2 pr: Paginate or columnate files for printing
- 4.3 fold: Wrap input lines to fit in specified width
5 Output of parts of files
- 5.1 head: Output the first part of files
- 5.2 tail: Output the last part of files
- 5.3 split: Split a file into pieces.
- 5.4 csplit: Split a file into context-determined pieces
6 Summarizing files
- 6.1 wc: Print newline, word, and byte counts
- 6.2 sum: Print checksum and block counts
- 6.3 cksum: Print and verify file checksums
- 6.4 md5sum: Print or check MD5 digests
- 6.5 b2sum: Print or check BLAKE2 digests
- 6.6 sha1sum: Print or check SHA-1 digests
- 6.7 sha2 utilities: Print or check SHA-2 digests
7 Operating on sorted files
- 7.1 sort: Sort text files
- 7.2 shuf: Shuffling text
- 7.3 uniq: Uniquify files
- 7.4 comm: Compare two sorted files line by line
- 7.5 ptx: Produce permuted indexes
- 7.6 tsort: Topological sort
  - 7.6.1 tsort: Background
8 Operating on fields
- 8.1 cut: Print selected parts of lines
- 8.2 paste: Merge lines of files
- 8.3 join: Join lines on a common field
9 Operating on characters
- 9.1 tr: Translate, squeeze, and/or delete characters
- 9.2 expand: Convert tabs to spaces
- 9.3 unexpand: Convert spaces to tabs
10 Directory listing
- 10.1 ls: List directory contents
- 10.2 dir: Briefly list directory contents
- 10.3 vdir: Verbosely list directory contents
- 10.4 dircolors: Color setup for ls
11 Basic operations
- 11.1 cp: Copy files and directories
- 11.2 dd: Convert and copy a file
- 11.3 install: Copy files and set attributes
- 11.4 mv: Move (rename) files
- 11.5 rm: Remove files or directories
- 11.6 shred: Remove files more securely
12 Special file types
- 12.1 link: Make a hard link via the link syscall
- 12.2 ln: Make links between files
- 12.3 mkdir: Make directories
- 12.4 mkfifo: Make FIFOs (named pipes)
- 12.5 mknod: Make block or character special files
- 12.6 readlink: Print value of a symlink or canonical file name
- 12.7 rmdir: Remove empty directories
- 12.8 unlink: Remove files via the unlink syscall
13 Changing file attributes
- 13.1 chown: Change file owner and group
- 13.2 chgrp: Change group ownership
- 13.3 chmod: Change access permissions
- 13.4 touch: Change file timestamps
14 File space usage
- 14.1 df: Report file system space usage
- 14.2 du: Estimate file space usage
- 14.3 stat: Report file or file system status
- 14.4 sync: Synchronize cached writes to persistent storage
- 14.5 truncate: Shrink or extend the size of a file
15 Printing text
- 15.1 echo: Print a line of text
- 15.2 printf: Format and print data
- 15.3 yes: Print a string until interrupted
16 Conditions
- 16.1 false: Do nothing, unsuccessfully
- 16.2 true: Do nothing, successfully
- 16.3 test: Check file types and compare values
- 16.4 expr: Evaluate expressions
17 Redirection
- 17.1 tee: Redirect output to multiple files or processes
18 File name manipulation
- 18.1 basename: Strip directory and suffix from a file name
- 18.2 dirname: Strip last file name component
- 18.3 pathchk: Check file name validity and portability
- 18.4 mktemp: Create temporary file or directory
- 18.5 realpath: Print the resolved file name.
  - 18.5.1 Realpath usage examples
19 Working context
- 19.1 pwd: Print working directory
- 19.2 stty: Print or change terminal characteristics
- 19.3 printenv: Print all or some environment variables
- 19.4 tty: Print file name of terminal on standard input
20 User information
- 20.1 id: Print user identity
- 20.2 logname: Print current login name
- 20.3 whoami: Print effective user name
- 20.4 groups: Print group names a user is in
- 20.5 users: Print login names of users currently logged in
- 20.6 who: Print who is currently logged in
- 20.7 pinky: Print information about users
21 System context
- 21.1 date: Print or set system date and time
- 21.2 arch: Print machine hardware name
- 21.3 nproc: Print the number of available processors
- 21.4 uname: Print system information
- 21.5 hostname: Print or set system name
- 21.6 hostid: Print numeric host identifier
- 21.7 uptime: Print system uptime and load
22 SELinux context
- 22.1 chcon: Change SELinux context of file
- 22.2 runcon: Run a command in specified SELinux context
23 Modified command invocation
- 23.1 chroot: Run a command with a different root directory
- 23.2 env: Run a command in a modified environment
- 23.3 nice: Run a command with modified niceness
- 23.4 nohup: Run a command immune to hangups
- 23.5 stdbuf: Run a command with modified I/O stream buffering
- 23.6 timeout: Run a command with a time limit
24 Process control
- 24.1 kill: Send a signal to processes
25 Delaying
- 25.1 sleep: Delay for a specified time
26 Numeric operations
- 26.1 factor: Print prime factors
- 26.2 numfmt: Reformat numbers
- 26.3 seq: Print numeric sequences
27 File permissions
- 27.1 Structure of File Mode Bits
- 27.2 Symbolic Modes
- 27.3 Numeric Modes
- 27.4 Operator Numeric Modes
- 27.5 Directories and the Set-User-ID and Set-Group-ID Bits
28 File timestamps
29 Date input formats
- 29.1 General date syntax
- 29.2 Calendar date items
- 29.3 Time of day items
- 29.4 Time zone items
- 29.5 Combined date and time of day items
- 29.6 Day of week items
- 29.7 Relative items in date strings
- 29.8 Pure numbers in date strings
- 29.9 Seconds since the Epoch
- 29.10 Specifying time zone rules
- 29.11 Authors of parse_datetime
30 Version sort ordering
- 30.1 Version sort overview
- 30.2 Version sort implementation
- 30.3 Differences from Debian version sort
- 30.4 Advanced Topics
31 Opening the Software Toolbox
- Toolbox Introduction
- I/O Redirection
- The who Command
- The cut Command
- The sort Command
- The uniq Command
- Putting the Tools Together
Appendix A GNU Free Documentation License
Index

GNU Coreutils

Table of Contents

Short Table of Contents