NAME

test − condition command

SYNOPSIS

test expr

DESCRIPTION

test evaluates the expression expr, and if its value is true, returns zero exit status; otherwise, a non zero exit status is returned. test returns a non zero exit if there are no arguments. 

The following primitives are used to construct expr.

−r file true, if the file exists and is readable. 

−w file true, if the file exists and is writable. 

−f file true, if the file exists and is not a directory. 

−d file true, if the file exists exists and is a directory. 

−s file true, if the file exists and has a size greater than zero. 

−t [ fildes ]
true, if the open file with a file descriptor number which is fildes (1 by default) is associated with a terminal device. 

−z s1 true, if the length of string s1 is zero. 

−n s1 true, if the length of the string s1 is nonzero. 

s1 = s2 true, if the strings s1 and s2 are equal. 

s1 != s2 true, if the strings s1 and s2 are not equal. 

s1 true, if s1 is not the null string. 

n1 −eq n2
true, if the integers n1 and n2 are algebraically equal.  Any of the comparisons −ne, −gt, −ge, −lt, or −le may be used in place of −eq. 

The following primaries may be combined with the following operators:

!  unary negation operator

−a binary and operator

−o binary or operator

( expr )
parentheses for grouping.

−a has higher precedence than −o.  Notice that all the operators and flags are separate arguments to test. Also note that parentheses are meaningful to the Shell and must be escaped.

SEE ALSO

sh(1), find(1)

November 02, 1983  —  %W%%Q%%Y%