выполнять расширения слов (perform word expansions)
Возвращаемое значение (Return value)
Upon successful completion, wordexp() shall return 0. Otherwise,
a non-zero value, as described in <wordexp.h>, shall be returned
to indicate an error. If wordexp() returns the value
WRDE_NOSPACE, then pwordexp->we_wordc and pwordexp->we_wordv
shall be updated to reflect any words that were successfully
expanded. In other error cases, if the WRDE_APPEND flag was
specified, pwordexp->we_wordc and pwordexp->we_wordv shall not be
modified.
The wordfree() function shall not return a value.