WORDEXP(3) | Library Functions Manual | WORDEXP(3) |
wordexp
— perform
shell-style word expansions
#include
<wordexp.h>
int
wordexp
(const
char * restrict words,
wordexp_t * restrict we,
int flags);
void
wordfree
(wordexp_t
*we);
The
wordexp
()
function performs shell-style word expansion on words
and places the list of words into the we_wordv member
of we, and the number of words into
we_wordc.
The flags argument is the bitwise inclusive OR of any of the following constants:
WRDE_APPEND
wordexp
().WRDE_DOOFFS
NULL
pointers as are specified by the
we_offs member of we are added
to the front of we_wordv.WRDE_NOCMD
WRDE_REUSE
wordexp
() but has not been passed to
wordfree
(). The implementation may reuse the space
allocated to it.WRDE_SHOWERR
WRDE_UNDEF
The wordexp_t structure is defined in
<wordexp.h>
as:
typedef struct { size_t we_wordc; /* count of words matched */ char **we_wordv; /* pointer to list of words */ size_t we_offs; /* slots to reserve in we_wordv */ } wordexp_t;
The
wordfree
()
function frees the memory allocated by
wordexp
().
The wordexp
() function is implemented as a
wrapper around the undocumented wordexp
shell
built-in command.
The wordexp
() function returns zero if
successful, otherwise it returns one of the following error codes:
WRDE_BADCHAR
|
’,
‘&
’,
‘;
’,
‘<
’,
‘>
’,
‘(
’,
‘)
’,
‘{
’,
‘}
’.WRDE_BADVAL
WRDE_UNDEF
is set in
flags.WRDE_CMDSUB
WRDE_NOCMD
is set in
flags.WRDE_NOSPACE
WRDE_SYNTAX
The wordfree
() function returns no
value.
IFS
Invoke the editor on all .c files in the current directory and /etc/motd (error checking omitted):
wordexp_t we; wordexp("${EDITOR:-vi} *.c /etc/motd", &we, 0); execvp(we.we_wordv[0], we.we_wordv);
Diagnostic messages from the shell are written to the standard
error output if WRDE_SHOWERR
is set in
flags.
The wordexp
() and
wordfree
() functions conform to
IEEE Std 1003.1-2001 (“POSIX.1”).
Do not pass untrusted user data to
wordexp
(), regardless of whether the
WRDE_NOCMD
flag is set. The
wordexp
() function attempts to detect input that
would cause commands to be executed before passing it to the shell but it
does not use the same parser so it may be fooled.
The current wordexp
() implementation does
not recognize multibyte characters, since the shell (which it invokes to
perform expansions) does not.
July 29, 2004 | macOS 14.6 |