argz_create(3) — Linux manual page


ARGZ_ADD(3)               Linux Programmer's Manual              ARGZ_ADD(3)

NAME         top

       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         top

       #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);

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

       void argz_extract(const 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(const 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         top

       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         top

       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

ATTRIBUTES         top

       For an explanation of the terms used in this section, see

       │Interface                         Attribute     Value   │
       │argz_add(), argz_add_sep(),       │ Thread safety │ MT-Safe │
       │argz_append(), argz_count(),      │               │         │
       │argz_create(), argz_create_sep(), │               │         │
       │argz_delete(), argz_extract(),    │               │         │
       │argz_insert(), argz_next(),       │               │         │
       │argz_replace(), argz_stringify()  │               │         │

CONFORMING TO         top

       These functions are a GNU extension.  Handle with care.

BUGS         top

       Argz vectors without a terminating null byte may lead to Segmentation

SEE ALSO         top


COLOPHON         top

       This page is part of release 5.08 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at

                                 2019-03-06                      ARGZ_ADD(3)