argz(3)

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);

   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

   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.

ATTRIBUTES

   For   an   explanation   of   the  terms  used  in  this  section,  see
   attributes(7).

   
   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

   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 4.09 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
   https://www.kernel.org/doc/man-pages/.

                              2015-03-02                       ARGZ_ADD(3)

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