Chapter 9. Commands and Utilities

9.1. Commands and Utilities

Table 9-1 lists the Commands and Utilities required to be present on a conforming system. These commands and utilities shall behave as described in the relevant underlying specification, with the following exceptions:

  1. If any operand (except one which follows --) starts with a hyphen, the behavior is unspecified.

    Rationale (Informative): Applications should place options before operands, or use --, as needed. This text is needed because GNU option parsing differs from POSIX. For example, ls . -a in GNU ls means to list the current directory, showing all files (that is, "." is an operand and -a is an option). In POSIX, "." and -a are both operands, and the command means to list the current directory, and also the file named -a. Suggesting that applications rely on the setting of the POSIXLY_CORRECT environment variable, or try to set it, seems worse than just asking the applictions to invoke commands in ways which work with either the POSIX or GNU behaviors.

The behavior of the interfaces described in this section is specified by the following standards.

this specification
ISO POSIX (2003)

Table 9-1. Commands and Utilities

[ [1]ar [2]at [2]awk [2]basename [1]
batch [2]bc [2]cat [1]chfn [2]chgrp [2]
chmod [1]chown [2]chsh [2]cksum [1]cmp [1]
col [2]comm [1]cp [1]cpio [2]crontab [2]
csplit [1]cut [2]date [1]dd [1]df [2]
diff [1]dirname [1]dmesg [2]du [2]echo [2]
egrep [2]env [1]expand [1]expr [1]false [1]
fgrep [2]file [2]find [2]fold [1]fuser [2]
gencat [1]getconf [1]gettext [2]grep [2]groupadd [2]
groupdel [2]groupmod [2]groups [2]gunzip [2]gzip [2]
head [1]hostname [2]iconv [1]id [1]install [2]
install_initd [2]ipcrm [2]ipcs [2]join [1]kill [1]
killall [2]ln [1]locale [1]localedef [1]logname [1]
lpr [2]ls [2]lsb_release [2]m4 [2]make [1]
man [1]md5sum [2]mkdir [1]mkfifo [1]mknod [2]
mktemp [2]more [2]mount [2]msgfmt [2]mv [1]
newgrp [2]nice [1]nl [1]nohup [1]od [2]
passwd [2]paste [1]patch [2]pathchk [1]pidof [2]
pr [1]printf [1]ps [1]pwd [1]remove_initd [2]
renice [2]rm [1]rmdir [1]sed [2]sendmail [2]
sh [1]shutdown [2]sleep [1]sort [1]split [1]
strip [1]stty [1]su [2]sync [2]tail [1]
tar [2]tee [1]test [1]time [1]touch [1]
tr [1]true [1]tsort [1]tty [1]umount [2]
uname [1]unexpand [1]uniq [1]useradd [2]userdel [2]
usermod [2]wc [1]xargs [2]  

Referenced Specification(s)