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 file    True if the file exists (is accessible) and is readable.
       -w file    True if the file exists and is writable.
       -x file    True if the file exists and has execute permission.
       -e file    True if the file exists.
       -f file    True if the file exists and is a plain file.
       -d file    True if the file 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 whose file descriptor number is fildes (1 by default) is the  same  file
                  as /dev/cons.
       -A file    True if the file exists and is append-only.
       -L file    True if the file exists and is exclusive-use.
       -Tfile     True if the file exists and is temporary.
       s1 = s2    True 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 b    True if file a is newer than (modified after) file b.
       a -ot b    True 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 operators:

       !         unary negation operator
       -o        binary or operator
       -a        binary 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 arguments 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 purported string "-c" as an option.

              if (test $1 '=' "-c") echo OK # wrong!

       A better way is

              if (~ $1 -c) echo OK

       Test whether is in the current directory.

              test -f abc -o -d abc

SOURCE

       /src/cmd/test.c

SEE ALSO

       rc(1)

                                                                                                    TEST(1plan9)