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<H1>ARGZ_ADD</H1>
Section: Linux Programmer's Manual (3)<BR>Updated: 2019-03-06<BR><A HREF="#index">Index</A>
<A HREF="/cgi-bin/man/man2html">Return to Main Contents</A><HR>
<A NAME="lbAB">&nbsp;</A>
<H2>NAME</H2>
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
<A NAME="lbAC">&nbsp;</A>
<H2>SYNOPSIS</H2>
<PRE>
<B>#include &lt;<A HREF="file:///usr/include/argz.h">argz.h</A>&gt;</B>
<B>error_t argz_add(char **</B><I>argz</I><B>, size_t *</B><I>argz_len</I><B>, const char *</B><I>str</I><B>);</B>
<B>error_t argz_add_sep(char **</B><I>argz</I><B>, size_t *</B><I>argz_len</I><B>,</B>
<B> const char *</B><I>str</I><B>, int </B><I>delim</I><B>);</B>
<B>error_t argz_append(char **</B><I>argz</I><B>, size_t *</B><I>argz_len</I><B>,</B>
<B> const char *</B><I>buf</I><B>, size_t </B><I>buf_len</I><B>);</B>
<B>size_t argz_count(const char *</B><I>argz</I><B>, size_t </B><I>argz_len</I><B>);</B>
<B>error_t argz_create(char * const </B><I>argv</I><B>[], char **</B><I>argz</I><B>,</B>
<B> size_t *</B><I>argz_len</I><B>);</B>
<B>error_t argz_create_sep(const char *</B><I>str</I><B>, int </B><I>sep</I><B>, char **</B><I>argz</I><B>,</B>
<B> size_t *</B><I>argz_len</I><B>);</B>
<B>void argz_delete(char **</B><I>argz</I><B>, size_t *</B><I>argz_len</I><B>, char *</B><I>entry</I><B>);</B>
<B>void argz_extract(const char *</B><I>argz</I><B>, size_t </B><I>argz_len</I><B>, char **</B><I>argv</I><B>);</B>
<B>error_t argz_insert(char **</B><I>argz</I><B>, size_t *</B><I>argz_len</I><B>, char *</B><I>before</I><B>,</B>
<B> const char *</B><I>entry</I><B>);</B>
<B>char *argz_next(const char *</B><I>argz</I><B>, size_t </B><I>argz_len</I><B>, const char *</B><I>entry</I><B>);</B>
<B>error_t argz_replace(char **</B><I>argz</I><B>, size_t *</B><I>argz_len</I><B>, const char *</B><I>str</I><B>,</B>
<B> const char *</B><I>with</I><B>, unsigned int *</B><I>replace_count</I><B>);</B>
<B>void argz_stringify(char *</B><I>argz</I><B>, size_t </B><I>len</I><B>, int </B><I>sep</I><B>);</B>
</PRE>
<A NAME="lbAD">&nbsp;</A>
<H2>DESCRIPTION</H2>
These functions are glibc-specific.
<P>
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.
<P>
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
<B><A HREF="/cgi-bin/man/man2html?3+malloc">malloc</A></B>(3),
so that
<B><A HREF="/cgi-bin/man/man2html?3+free">free</A></B>(3)
can be used to dispose of them again.
<P>
<B>argz_add</B>()
adds the string
<I>str</I>
at the end of the array
<I>*argz</I>,
and updates
<I>*argz</I>
and
<I>*argz_len</I>.
<P>
<B>argz_add_sep</B>()
is similar, but splits the string
<I>str</I>
into substrings separated by the delimiter
<I>delim</I>.
For example, one might use this on a UNIX search path with
delimiter ':'.
<P>
<B>argz_append</B>()
appends the argz vector
(<I>buf</I>,&nbsp;<I>buf_len</I>)
after
(<I>*argz</I>,&nbsp;<I>*argz_len</I>)
and updates
<I>*argz</I>
and
<I>*argz_len</I>.
(Thus,
<I>*argz_len</I>
will be increased by
<I>buf_len</I>.)
<P>
<B>argz_count</B>()
counts the number of strings, that is,
the number of null bytes ('\0'), in
(<I>argz</I>,&nbsp;<I>argz_len</I>).
<P>
<B>argz_create</B>()
converts a UNIX-style argument vector
<I>argv</I>,
terminated by
<I>(char&nbsp;*)&nbsp;0</I>,
into an argz vector
(<I>*argz</I>,&nbsp;<I>*argz_len</I>).
<P>
<B>argz_create_sep</B>()
converts the null-terminated string
<I>str</I>
into an argz vector
(<I>*argz</I>,&nbsp;<I>*argz_len</I>)
by breaking it up at every occurrence of the separator
<I>sep</I>.
<P>
<B>argz_delete</B>()
removes the substring pointed to by
<I>entry</I>
from the argz vector
(<I>*argz</I>,&nbsp;<I>*argz_len</I>)
and updates
<I>*argz</I>
and
<I>*argz_len</I>.
<P>
<B>argz_extract</B>()
is the opposite of
<B>argz_create</B>().
It takes the argz vector
(<I>argz</I>,&nbsp;<I>argz_len</I>)
and fills the array starting at
<I>argv</I>
with pointers to the substrings, and a final NULL,
making a UNIX-style argv vector.
The array
<I>argv</I>
must have room for
<I>argz_count</I>(<I>argz</I>, <I>argz_len</I>) + 1
pointers.
<P>
<B>argz_insert</B>()
is the opposite of
<B>argz_delete</B>().
It inserts the argument
<I>entry</I>
at position
<I>before</I>
into the argz vector
(<I>*argz</I>,&nbsp;<I>*argz_len</I>)
and updates
<I>*argz</I>
and
<I>*argz_len</I>.
If
<I>before</I>
is NULL, then
<I>entry</I>
will inserted at the end.
<P>
<B>argz_next</B>()
is a function to step trough the argz vector.
If
<I>entry</I>
is NULL, the first entry is returned.
Otherwise, the entry
following is returned.
It returns NULL if there is no following entry.
<P>
<B>argz_replace</B>()
replaces each occurrence of
<I>str</I>
with
<I>with</I>,
reallocating argz as necessary.
If
<I>replace_count</I>
is non-NULL,
<I>*replace_count</I>
will be incremented by the number of replacements.
<P>
<B>argz_stringify</B>()
is the opposite of
<B>argz_create_sep</B>().
It transforms the argz vector into a normal string by replacing
all null bytes ('\0') except the last by
<I>sep</I>.
<A NAME="lbAE">&nbsp;</A>
<H2>RETURN VALUE</H2>
All argz functions that do memory allocation have a return type of
<I>error_t</I>,
and return 0 for success, and
<B>ENOMEM</B>
if an allocation error occurs.
<A NAME="lbAF">&nbsp;</A>
<H2>ATTRIBUTES</H2>
For an explanation of the terms used in this section, see
<B><A HREF="/cgi-bin/man/man2html?7+attributes">attributes</A></B>(7).
<TABLE BORDER>
<TR VALIGN=top><TD><B>Interface</B></TD><TD><B>Attribute</B></TD><TD><B>Value</B><BR></TD></TR>
<TR VALIGN=top><TD>
<B>argz_add</B>(),
<B>argz_add_sep</B>(),
<BR>
<B>argz_append</B>(),
<B>argz_count</B>(),
<BR>
<B>argz_create</B>(),
<B>argz_create_sep</B>(),
<BR>
<B>argz_delete</B>(),
<B>argz_extract</B>(),
<BR>
<B>argz_insert</B>(),
<B>argz_next</B>(),
<BR>
<B>argz_replace</B>(),
<B>argz_stringify</B>()
</TD><TD>Thread safety</TD><TD>MT-Safe<BR></TD></TR>
</TABLE>
<P>
<A NAME="lbAG">&nbsp;</A>
<H2>CONFORMING TO</H2>
These functions are a GNU extension.
Handle with care.
<A NAME="lbAH">&nbsp;</A>
<H2>BUGS</H2>
Argz vectors without a terminating null byte may lead to
Segmentation Faults.
<A NAME="lbAI">&nbsp;</A>
<H2>SEE ALSO</H2>
<B><A HREF="/cgi-bin/man/man2html?3+envz_add">envz_add</A></B>(3)
<A NAME="lbAJ">&nbsp;</A>
<H2>COLOPHON</H2>
This page is part of release 5.05 of the Linux
<I>man-pages</I>
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
<A HREF="https://www.kernel.org/doc/man-pages/.">https://www.kernel.org/doc/man-pages/.</A>
<P>
<HR>
<A NAME="index">&nbsp;</A><H2>Index</H2>
<DL>
<DT id="1"><A HREF="#lbAB">NAME</A><DD>
<DT id="2"><A HREF="#lbAC">SYNOPSIS</A><DD>
<DT id="3"><A HREF="#lbAD">DESCRIPTION</A><DD>
<DT id="4"><A HREF="#lbAE">RETURN VALUE</A><DD>
<DT id="5"><A HREF="#lbAF">ATTRIBUTES</A><DD>
<DT id="6"><A HREF="#lbAG">CONFORMING TO</A><DD>
<DT id="7"><A HREF="#lbAH">BUGS</A><DD>
<DT id="8"><A HREF="#lbAI">SEE ALSO</A><DD>
<DT id="9"><A HREF="#lbAJ">COLOPHON</A><DD>
</DL>
<HR>
This document was created by
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using the manual pages.<BR>
Time: 00:05:35 GMT, March 31, 2021
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