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TEST(1) General Commands Manual TEST(1) NAME test, [, newer - condition commands SYNOPSIS test expr [ expr ] newer file1 file2 DESCRIPTION Test evaluates the expression expr. If the value is true the exit sta- tus is 0; otherwise the exit status is nonzero. If there are no argu- ments the exit status is nonzero. 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. -c file True if the file exists and is a character special file. -b file True if the file exists and is a block special file. -L file True if the file is a symbolic link. -u file True if the file exists and has set userid permission. -g file True if the file exists and has set groupid permission. -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 associated with a terminal device. -S True if the effective userid is zero. 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.) -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. 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. Notice that all the operators and flags are separate arguments to test. Notice also that parentheses are meaningful to the Shell and must be escaped. [ is a synonym for test, except that [ requires a closing ]. Newer returns a zero exit code if file1 exists and file2 does not, or if file1 and file2 both exist and file1 was modified at least as re- cently as file2. It returns a non-zero return code otherwise. EXAMPLES Test is a dubious way to check for specific character strings: it uses a process to do what a shell case statement can do. The first example is not only inefficient but wrong, because test understands the pur- ported string "-c" as an option. Furthermore $1 might be empty. if test $1 = "-c" # wrong! then echo OK fi A correct way is case "$1" in -c) echo OK esac Test whether is in the current directory. test -e abc -o -L abc SEE ALSO sh(1), find(1) TEST(1)