argz_add(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

LIBRARY
Standard C library (libc, -lc)

SYNOPSIS
#include <argz.h>

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

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

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

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

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

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

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

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

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

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

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);

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 through 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 (an integer type), 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
 | Thread safety | MT-Safe

STANDARDS
GNU.

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

SEE ALSO
envz_add(3)