.\"     $NetBSD: efun.3,v 1.10 2010/05/03 05:40:37 jruoho Exp $
.\"
.\" Copyright (c) 2006 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Christos Zoulas.
.\"
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.\" modification, are permitted provided that the following conditions
.\" are met:
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.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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.Dd April 26, 2011
.Dt EFUN 3
.Os
.Sh NAME
.Nm esetfunc ,
.Nm emalloc ,
.Nm ecalloc ,
.Nm erealloc ,
.Nm estrdup ,
.Nm estrndup ,
.Nm estrlcat ,
.Nm estrlcpy ,
.Nm easprintf
.Nd error-checked utility functions
.Sh LIBRARY
.Lb libutil
.Sh SYNOPSIS
.In sys/types.h
.In libutil.h
.Ft void (*)(int, const char *, ...)
.Fn esetfunc "void (*)(int, const char *, ...)"
.Ft void *
.Fn ecalloc "size_t n" "size_t c"
.Ft void *
.Fn emalloc "size_t n"
.Ft void *
.Fn erealloc "void *p" "size_t n"
.Ft char *
.Fn estrdup "const char *s"
.Ft char *
.Fn estrndup "const char *s" "size_t len"
.Ft size_t
.Fn estrlcat "char *dst" "const char *src" "size_t len"
.Ft size_t
.Fn estrlcpy "char *dst" "const char *src" "size_t len"
.Ft int
.Fn easprintf "char ** restrict str" "const char * restrict fmt" "..."
.Sh DESCRIPTION
The
.Fn ecalloc ,
.Fn emalloc ,
.Fn erealloc ,
.Fn estrdup ,
.Fn estrndup ,
.Fn estrlcat ,
.Fn estrlcpy ,
and
.Fn easprintf
functions
operate exactly as the corresponding functions that do not start with an
.Sq e
except that in case of an error, they call
the installed error handler that can be configured with
.Fn esetfunc .
.Pp
For the string handling functions, it is an error when the destination
buffer is not large enough to hold the complete string.
For functions that allocate memory or open a file, it is an error when
they would return a null pointer.
The default error handler is
.Xr err 3 .
The function
.Fn esetfunc
returns the previous error handler function.
A
.Dv NULL
error handler will just call
.Xr exit 3 .
.Sh SEE ALSO
.Xr asprintf 3 ,
.Xr calloc 3 ,
.Xr err 3 ,
.Xr exit 3 ,
.Xr fopen 3 ,
.Xr malloc 3 ,
.Xr realloc 3 ,
.Xr strdup 3 ,
.Xr strlcat 3 ,
.Xr strlcpy 3 ,
.Xr strndup 3
.\".Xr vasprintf 3
.Sh HISTORY
The error functions first appeared in
.Dx 2.11 .
They are originally from
.Nx .