сортировать, объединять или проверять последовательность текстовых файлов (sort, merge, or sequence check text files)
Статус выхода (Exit)
The following exit values shall be returned:
0 All input files were output successfully, or -c was
specified and the input file was correctly sorted.
1 Under the -c option, the file was not ordered as specified,
or if the -c and -u options were both specified, two input
lines were found with equal keys.
>1 An error occurred.
