.\" zip_source_file.mdoc -- create data source from a file
.\" Copyright (C) 2004-2021 Dieter Baron and Thomas Klausner
.\"
.\" This file is part of libzip, a library to manipulate ZIP archives.
.\" The authors can be contacted at <libzip@nih.at>
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.Dd December 18, 2017
.Dt ZIP_SOURCE_FILE 3
.Os
.Sh NAME
.Nm zip_source_file ,
.Nm zip_source_file_create
.Nd create data source from a file
.Sh LIBRARY
libzip (-lzip)
.Sh SYNOPSIS
.In zip.h
.Ft zip_source_t *
.Fn zip_source_file "zip_t *archive" "const char *fname" "zip_uint64_t start" "zip_int64_t len"
.Ft zip_source_t *
.Fn zip_source_file_create "const char *fname" "zip_uint64_t start" "zip_int64_t len" "zip_error_t *error"
.Sh DESCRIPTION
The functions
.Fn zip_source_file
and
.Fn zip_source_file_create
create a zip source from a file.
They open
.Ar fname
and read
.Ar len
bytes from offset
.Ar start
from it.
If
.Ar len
is 0 or \-1, the whole file (starting from
.Ar start )
is used.
.Pp
If the file supports seek, the source can be used to open a zip archive from.
.Pp
The file is opened and read when the data from the source is used, usually by
.Fn zip_close
or
.Fn zip_open_from_source .
.Sh RETURN VALUES
Upon successful completion, the created source is returned.
Otherwise,
.Dv NULL
is returned and the error code in
.Ar archive
or
.Ar error
is set to indicate the error.
.Sh ERRORS
.Fn zip_source_file
and
.Fn zip_source_file_create
fail if:
.Bl -tag -width Er
.It Bq Er ZIP_ER_INVAL
.Ar fname ,
.Ar start ,
or
.Ar len
are invalid.
.It Bq Er ZIP_ER_MEMORY
Required memory could not be allocated.
.It Bq Er ZIP_ER_OPEN
Opening
.Ar fname
failed.
.El
.Sh SEE ALSO
.Xr libzip 3 ,
.Xr zip_file_add 3 ,
.Xr zip_file_replace 3 ,
.Xr zip_source 3
.Sh HISTORY
.Fn zip_source_file
and
.Fn zip_source_file_create
were added in libzip 1.0.
.Sh AUTHORS
.An -nosplit
.An Dieter Baron Aq Mt dillo@nih.at
and
.An Thomas Klausner Aq Mt tk@giga.or.at