NAME

       argz_add, argz_add_sep, argz_append, argz_count, argz_create, argz_create_sep, argz_delete, argz_extract,
       argz_insert, argz_next, argz_replace, argz_stringify - functions to handle an argz list

SYNOPSIS

       #include <argz.h>

       error_t argz_add(char **argz, size_t *argz_len, const char *str);

       error_t argz_add_sep(char **argz, size_t *argz_len,
                            const char *str, int delim);

       error_t argz_append(char **argz, size_t *argz_len,
                            const char *buf, size_t buf_len);

       size_t argz_count(const char *argz, size_t argz_len);

       error_t argz_create(char * const argv[], char **argz,
                            size_t *argz_len);

       error_t argz_create_sep(const char *str, int sep, char **argz,
                            size_t *argz_len);

       error_t argz_delete(char **argz, size_t *argz_len, char *entry);

       void argz_extract(char *argz, size_t argz_len, char  **argv);

       error_t argz_insert(char **argz, size_t *argz_len, char *before,
                            const char *entry);

       char *argz_next(char *argz, size_t argz_len, const char *entry);

       error_t argz_replace(char **argz, size_t *argz_len, const char *str,
                            const char *with, unsigned int *replace_count);

       void argz_stringify(char *argz, size_t len, int sep);

DESCRIPTION

       These functions are glibc-specific.

       An argz vector is a pointer to a character buffer together with a length.  The intended interpretation of
       the  character  buffer  is an array of strings, where the strings are separated by null bytes ('\0').  If
       the length is nonzero, the last byte of the buffer must be a null byte.

       These functions are for handling argz vectors.  The pair (NULL,0) is an  argz  vector,  and,  conversely,
       argz  vectors  of  length  0  must  have NULL pointer.  Allocation of nonempty argz vectors is done using
       malloc(3), so that free(3) can be used to dispose of them again.

       argz_add() adds the string str at the end of the array *argz, and updates *argz and *argz_len.

       argz_add_sep() is similar, but splits the string str into substrings separated by  the  delimiter  delim.
       For example, one might use this on a UNIX search path with delimiter ':'.

       argz_append()  appends  the  argz  vector  (buf, buf_len)  after (*argz, *argz_len) and updates *argz and
       *argz_len.  (Thus, *argz_len will be increased by buf_len.)

       argz_count() counts the number of strings, that is, the number of null bytes ('\0'), in (argz, argz_len).

       argz_create() converts a UNIX-style argument vector argv, terminated by (char *) 0, into an  argz  vector
       (*argz, *argz_len).

       argz_create_sep()  converts  the  null-terminated  string  str  into an argz vector (*argz, *argz_len) by
       breaking it up at every occurrence of the separator sep.

       argz_delete() removes the substring pointed to by entry  from  the  argz  vector  (*argz, *argz_len)  and
       updates *argz and *argz_len.

       argz_extract() is the opposite of argz_create().  It takes the argz vector (argz, argz_len) and fills the
       array starting at argv with pointers to the substrings, and  a  final  NULL,  making  a  UNIX-style  argv
       vector.  The array argv must have room for argz_count(argz, argz_len) + 1 pointers.

       argz_insert()  is  the  opposite of argz_delete().  It inserts the argument entry at position before into
       the argz vector (*argz, *argz_len) and updates *argz and *argz_len.  If before is NULL, then  entry  will
       inserted at the end.

       argz_next() is a function to step trough the argz vector.  If entry is NULL, the first entry is returned.
       Otherwise, the entry following is returned.  It returns NULL if there is no following entry.

       argz_replace()  replaces  each  occurrence  of  str  with  with,  reallocating  argz  as  necessary.   If
       replace_count is non-NULL, *replace_count will be incremented by the number of replacements.

       argz_stringify()  is  the  opposite  of  argz_create_sep().   It transforms the argz vector into a normal
       string by replacing all null bytes ('\0') except the last by sep.

RETURN VALUE

       All argz functions that do memory allocation have a return type of error_t, and return 0 for success, and
       ENOMEM if an allocation error occurs.

CONFORMING TO

       These functions are a GNU extension.  Handle with care.

BUGS

       Argz vectors without a terminating null byte may lead to Segmentation Faults.

SEE ALSO

       envz_add(3)

COLOPHON

       This  page  is  part  of  release 3.54 of the Linux man-pages project.  A description of the project, and
       information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.

                                                   2007-05-18                                        ARGZ_ADD(3)