command(1) User Commands command(1)
command - execute a simple command
command [-p] command_name [argument...]
command [-v | -V] command_name
The command utility causes the shell to treat the arguments as a simple
command, suppressing the shell function lookup.
If the command_name is the same as the name of one of the special
built-in utilities, the special properties will not occur. In every
other respect, if command_name is not the name of a function, the
effect of command (with no options) will be the same as omitting com-
The command utility also provides information concerning how a command
name will be interpreted by the shell. See -v and -V.
The following options are supported:
-p Performs the command search using a default value for PATH
that is guaranteed to find all of the standard utilities.
-v Writes a string to standard output that indicates the path or
command that will be used by the shell, in the current shell
execution environment to invoke command_name, but does not
o Utilities, regular built-in utilities, command_names
including a slash character, and any implementation-pro-
vided functions that are found using the PATH variable
will be written as absolute path names.
o Shell functions, special built-in utilities, regular
built-in utilities not associated with a PATH search, and
shell reserved words will be written as just their names.
o An alias will be written as a command line that repre-
sents its alias definition.
o Otherwise, no output will be written and the exit status
will reflect that the name was not found.
-V Writes a string to standard output that indicates how the name
given in the command_name operand will be interpreted by the
shell, in the current shell execution environment, but does
not invoke command_name. Although the format of this string is
unspecified, it will indicate in which of the following cate-
gories command_name falls and include the information stated:
o Utilities, regular built-in utilities, and any implemen-
tation-provided functions that are found using the PATH
variable will be identified as such and include the
absolute path name in the string.
o Other shell functions will be identified as functions.
o Aliases will be identified as aliases and their defini-
tions will be included in the string.
o Special built-in utilities will be identified as special
o Regular built-in utilities not associated with a PATH
search will be identified as regular built-in utilities.
o Shell reserved words will be identified as reserved
The following operands are supported:
argument One of the strings treated as an argument to com-
command_name The name of a utility or a special built-in utility.
Example 1: Making a version of cd that always prints out the new work-
ing directory exactly once
command cd "$@" >/dev/null
Example 2: Starting off a ``secure shell script'' in which the script
avoids being spoofed by its parent
# The preceding value should be <space><tab><newline>.
# Set IFS to its default value.
# Unset all possible aliases.
# Note that unalias is escaped to prevent an alias
# being used for unalias.
unset -f command
# Ensure command is not a user function.
PATH="$(command -p getconf _CS_PATH):$PATH"
# Put on a reliable PATH prefix.
At this point, given correct permissions on the directories called by
PATH, the script has the ability to ensure that any utility it calls is
the intended one. It is being very cautious because it assumes that
implementation extensions may be present that would allow user func-
tions to exist when it is invoked. This capability is not specified by
this document, but it is not prohibited as an extension. For example,
the ENV variable precedes the invocation of the script with a user
startup script. Such a script could define functions to spoof the
See environ(5) for descriptions of the following environment variables
that affect the execution of command: LANG, LC_ALL, LC_CTYPE, LC_MES-
SAGES, and NLSPATH.
PATH Determine the search path used during the command search,
except as described under the -p option.
When the -v or -V options are specified, the following exit values are
0 Successful completion.
>>0 The command_name could not be found or an error occurred.
Otherwise, the following exit values are returned:
126 The utility specified by command_name was found but could not
127 An error occurred in the command utility or the utility speci-
fied by command_name could not be found.
Otherwise, the exit status of command will be that of the simple com-
mand specified by the arguments to command.
See attributes(5) for descriptions of the following attributes:
tab() allbox; cw(2.750000i)| cw(2.750000i) lw(2.750000i)|
lw(2.750000i). ATTRIBUTE TYPEATTRIBUTE VALUE AvailabilitySUNWcsu
sh(1), type(1), attributes(5), environ(5), standards(5)
SunOS 5.10 17 Jul 2002 command(1)