TEST(1) TEST(1)
NAME
test - set status according to condition
SYNOPSIS
test expr
DESCRIPTION
Test evaluates the expression expr. If the value is true the
exit status is null; otherwise the exit status is non-null.
If there are no arguments the exit status is non-null.
The following primitives are used to construct expr.
-r fileTrue if the file exists (is accessible) and is
readable.
-w fileTrue if the file exists and is writable.
-x fileTrue if the file exists and has execute permis-
sion.
-e fileTrue if the file exists.
-f fileTrue if the file exists and is a plain file.
-d fileTrue if the file exists and is a directory.
-s fileTrue if the file exists and has a size greater
than zero.
-t fildes True if the open file whose file descriptor num-
ber is fildes (1 by default) is the same file as
/dev/cons.
-A fileTrue if the file exists and is append-only.
-L fileTrue if the file exists and is exclusive-use.
-Tfile True if the file exists and is temporary.
s1 = s2True if the strings s1 and s2 are identical.
s1 != s2 True if the strings s1 and s2 are not identical.
s1 True if s1 is not the null string. (Deprecated.)
-n s1 True if the length of string s1 is non-zero.
-z s1 True if the length of string s1 is zero.
n1 -eq n2 True if the integers n1 and n2 are arithmetically
equal. Any of the comparisons -ne, -gt, -ge,
-lt, or -le may be used in place of -eq. The
(nonstandard) construct -l string, meaning the
length of string, may be used in place of an
integer.
a -nt bTrue if file a is newer than (modified after)
file b.
a -ot bTrue if file a is older than (modified before)
file b.
f -older t True if file f is older than (modified before)
time t. If t is a integer followed by the letters
y(years), M(months), d(days), h(hours),
m(minutes), or s(seconds), it represents current
time minus the specified time. If there is no
letter, it represents seconds since epoch. You
can also concatenate mixed units. For example,
3d12h means three days and twelve hours ago.
These primaries may be combined with the following opera-
tors:
! unary negation operator
-obinary or operator
-abinary and operator; higher precedence than -o
( expr ) parentheses for grouping.
The primitives -b, -u, -g, and -s return false; they are
recognized for compatibility with POSIX.
Notice that all the operators and flags are separate argu-
ments to test. Notice also that parentheses and equal signs
are meaningful to rc and must be enclosed in quotes.
EXAMPLES
Test is a dubious way to check for specific character
strings: it uses a process to do what an rc(1) match or
switch statement can do. The first example is not only
inefficient but wrong, because test understands the pur-
ported string -c as an option.
if (test $1 '=' -c) echo OK # wrong!
A better way is
if (~ $1 -c) echo OK
Test whether `abc' is in the current directory.
test -f abc -o -d abc
SOURCE
/sys/src/cmd/test.c
SEE ALSO
rc(1)
BUGS
Won't complain about extraneous arguments since there may be
arguments left unprocessed by short-circuit evaluation of -a
or -o.
