|  | 
 NAME     
 |  |  |  | test – set status according to condition 
 | 
 SYNOPSIS     
 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 n2True 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 tTrue 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
 These primaries may be combined with the following operators:|  |  |  | |  |  |  | days and twelve hours ago. | 
 | 
 !       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. 
 A better way is|  |  |  | if (test $1 '=' "−c") echo OK # wrong! 
 | 
 Test whether abc is in the current directory.
 
 | 
 SOURCE     
 SEE ALSO     
 BUGS     
 |  |  |  | Won’t complain about extraneous arguments since there may be arguments
    left unprocessed by short-circuit evaluation of −a or −o. 
 | 
 |  |