Glibc uses 'restrict' for some of the functions in this page: ============================= argz_add string/argz.h:76: error_t argz_add (char **restrict argz, size_t *restrict argz_len, const char *restrict str) THROW; ============================= argz_add_sep string/argz.h:82: error_t argz_add_sep (char **restrict argz, size_t *restrict argz_len, const char *restrict string, int delim) THROW; ============================= argz_append string/argz.h:70: error_t argz_append (char **restrict argz, size_t *restrict argz_len, const char *restrict buf, size_t buf_len) THROW; ============================= argz_count string/argz.h:54: size_t argz_count (const char *argz, size_t len) THROW attribute_pure__; ============================= argz_create string/argz.h:40: error_t argz_create (char *const argv[], char **restrict argz, size_t *restrict len) THROW; ============================= argz_create_sep string/argz.h:47: error_t argz_create_sep (const char *restrict string, int sep, char **restrict argz, size_t *restrict len) THROW; ============================= argz_delete string/argz.h:88: void argz_delete (char **restrict argz, size_t *restrict argz_len, char *restrict entry) THROW; ============================= argz_extract string/argz.h:61: void argz_extract (const char *restrict argz, size_t len, char **restrict argv) THROW; ============================= argz_insert string/argz.h:98: error_t argz_insert (char **restrict argz, size_t *restrict argz_len, char *restrict before, const char *restrict entry) THROW; ============================= argz_next string/argz.h:128: char *argz_next (const char *restrict argz, size_t argz_len, const char *restrict entry) THROW; ============================= argz_replace string/argz.h:106: error_t argz_replace (char **restrict argz, size_t *restrict argz_len, const char *restrict str, const char *restrict with, unsigned int *restrict replace_count); ============================= argz_stringify string/argz.h:67: void argz_stringify (char *argz, size_t len, int sep) THROW; Let's use it here too. Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com> Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>