1h5unjam(1)                  General Commands Manual                 h5unjam(1)
2
3
4

NAME

6       h5unjam - Extract the user block from a HDF5 file
7

SYNOPSIS

9       h5unjam -i in_file.h5 [-u user_block | --delete] [-o out_file.h5]
10

DESCRIPTION

12       h5unjam splits an HDF5 file, writing the user block to a file or stdout
13       and the HDF5 file to an HDF5 file with a header at byte 0  (i.e.,  with
14       no user block).
15
16       If  out_file.h5  is  given,  a  new file is created with the in_file.h5
17       without the user block. In this case, infile.h5 is unchanged.
18
19       If  out_file.h5  is  not  specified,  the  user_block  is  removed  and
20       in_file.h5 is rewritten, starting at byte 0.
21
22       If user_block is set, the user block will be written to user_block.  If
23       user_block is not set, the user block (if any) will be written to  std‐
24       out. If --delete is selected, the user block will not be not written.
25

EXAMPLE USAGE

27       For an HDF5 file, with_ub.h5, with a user block, extract the user block
28       to user_block.txt and the HDF5 file to wo_ub.h5.
29
30            h5unjam -i with_ub.h5 -u user_block.txt -i wo_ub.h5
31

RETURN VALUE

33       h5unjam returns the size of the output file, or -1 if an error occurs.
34

CAVEATS

36       This tool copies all the data (sequentially) in the file(s) to new off‐
37       sets. For a large file, this copy will take a long time.
38
39       The  most  efficient  way  to create a user block is to create the file
40       with a user block (see H5Pset_user_block), and  write  the  user  block
41       data into that space from a program.
42
43       The  user  block  is  completely  opaque to the HDF5 library and to the
44       h5jam and h5unjam tools.  The user block is simply read or written as a
45       string of bytes, which could be text or any kind of binary data.  It is
46       up to the user to know what the contents of the user  block  means  and
47       how to process it.
48
49       When  the  user block is extracted, all the data is written to the out‐
50       put, including any padding or unwritten data.
51
52       This tool moves the HDF5 file through byte copies, i.e.,  it  does  not
53       read or interpret the HDF5 objects.
54

SEE ALSO

56       h5dump(1),   h5ls(1),  h5diff(1),  h5import(1),  gif2h5(1),  h52gif(1),
57       h5perf(1), h5jam(1).
58
59
60
61                                                                    h5unjam(1)
Impressum