TEST(1) | General Commands Manual | TEST(1)

# NAME

`test`, `[` — condition evaluation utility

# SYNOPSIS

`test` | expression

`[` | expression `]`

# DESCRIPTION

The `test` utility evaluates the expression and, if it evaluates to true, returns a zero (true) exit status; otherwise it returns 1 (false). If no expression is given, `test` also returns 1 (false). The form `[` is an alias for `test`.

All operators and flags are separate arguments to the `test` utility. Symbolic links are followed for all primaries except `-h` and `-L`.

The following primaries are used to construct expression:

`-b` file
  True if file exists and is a block special file.
`-c` file
  True if file exists and is a character special file.
`-d` file
  True if file exists and is a directory.
`-e` file
  True if file exists (regardless of type).
`-f` file
  True if file exists and is a regular file.
`-G` file
  True if file exists and its group matches the effective group ID of this process.
`-g` file
  True if file exists and its set-group-ID flag is set.
`-h` file
  True if file exists and is a symbolic link. Identical to `-L`.
`-k` file
  True if file exists and its sticky bit is set.
`-L` file
  True if file exists and is a symbolic link. Identical to `-h`.
`-n` string
  True if the length of string is nonzero.
`-O` file
  True if file exists and its owner matches the effective user ID of this process.
`-p` file
  True if file is a named pipe (FIFO).
`-r` file
  True if file exists and is readable.
`-S` file
  True if file exists and is a socket.
`-s` file
  True if file exists and has a size greater than zero.
`-t` file_descriptor
  True if the file whose file descriptor number is file_descriptor is open and is associated with a terminal.
`-u` file
  True if file exists and its set-user-ID flag is set.
`-w` file
  True if file exists and is writable. True indicates only that the write flag is on. The file is not writable on a read-only file system even if this test indicates true.
`-x` file
  True if file exists and is executable. True indicates only that the execute flag is on. If file is a directory, true indicates that file can be searched.
`-z` string
  True if the length of string is zero.
file1 `-nt` file2
  True if file1 exists and is newer than file2.
file1 `-ot` file2
  True if file1 exists and is older than file2.
file1 `-ef` file2
  True if file1 and file2 exist and refer to the same file.
s1 `=` s2
  True if the strings s1 and s2 are identical.
s1 `!=` s2
  True if the strings s1 and s2 are not identical.
s1 `<` s2
  True if string s1 comes before s2 based on the ASCII value of their characters.
s1 `>` s2
  True if string s1 comes after s2 based on the ASCII value of their characters.
s1
  True if s1 is not the null string.
n1 `-eq` n2
  True if the integers n1 and n2 are algebraically equal.
n1 `-ne` n2
  True if the integers n1 and n2 are not algebraically equal.
n1 `-gt` n2
  True if the integer n1 is algebraically greater than the integer n2.
n1 `-ge` n2
  True if the integer n1 is algebraically greater than or equal to the integer n2.
n1 `-lt` n2
  True if the integer n1 is algebraically less than the integer n2.
n1 `-le` n2
  True if the integer n1 is algebraically less than or equal to the integer n2.

These primaries can be combined with the following operators. The `-a` operator has higher precedence than the `-o` operator.

`!` expression
  True if expression is false.
expression1 `-a` expression2
  True if both expression1 and expression2 are true.
expression1 `-o` expression2
  True if either expression1 or expression2 are true.
`(` expression `)`
  True if expression is true.

# EXIT STATUS

The `test` utility exits with one of the following values:

0
  Expression evaluated to true.
1
  Expression evaluated to false or expression was missing.
>1
  An error occurred.

# GRAMMAR AMBIGUITY

The `test` grammar is inherently ambiguous. In order to assure a degree of consistency, the cases described in IEEE Std 1003.2 (“POSIX.2”) section D11.2/4.62.4 are evaluated consistently according to the rules specified in the standards document. All other cases are subject to the ambiguity in the command semantics.

# SEE ALSO

ksh(1)

# STANDARDS

The `test` utility is compliant with the IEEE Std 1003.1-2008 (“POSIX.1”) specification.

The primaries `-G`, `-k`, `-O`, `-nt`, `-ot`, `-ef`, `<`, and `>` are extensions to that specification.

The operators `-a`, `-o`, and `()` are marked by IEEE Std 1003.1-2008 (“POSIX.1”) as part of X/Open System Interfaces and obsolete.

`test` also exists as a built-in to ksh(1), though with a different syntax.

# HISTORY

A `test` utility appeared in Version 7 AT&T UNIX.

June 18, 2024 | Debian