Essay About Open102 And Use Updateb

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all functions – o
obasis
file= obasis(filename)
or file= openb(filename)
or file= openb(filename, clogfile)
(If you typed help,openb and are reading this, then consider the
latter two forms. If you typed help,obasis, consider the first.
In either case, the original openb function is called basfix_openb.)
open the existing file FILENAME for read-only binary I/O.
(Use updateb or createb, respectively, to open an existing file
with read-write access or to create a new file.)
If the CLOGFILE argument is supplied, it represents the structure
of FILENAME in the Clog binary data description language.
After an openb, the file variable may be used to extract variables
from the file as if it were a structure instance. That is, the
expression “file.var” refers to the variable “var” in file “file”.
A complete list of the variable names present in the file may
be obtained using the get_vars function. If the file contains
history records, the jt and jc functions may be used to set the
current record — initially, the first record is current.
The restore function may be used to make memory copies of data
in the file; this will be faster than a large number of
references to “file.var”.
interpreted function, defined at i/basfix.i line 33
SEE ALSO:
updateb, createb, open, cd, show, jt, jc,
restore, get_vars, get_times, get_ncycs,
get_member, has_records, set_blocksize,
dump_clog, read_clog, recover_file,
openb_hooks, open102, close102, get_addrs,
baset, baget
op_test
op_test
op_test
op_test
opacset
opacset
interpreted function, defined at i/test2.i line 276
f= open(filename)
or f= open(filename, filemode)
or f= open(filename, filemode, errmode)
opens the file FILENAME according to FILEMODE (both are strings).
If ERRMODE is non-nil and non-zero, fail by returning nil F,
otherwise failure to open or create the file is a runtime error.
To use ERRMODE to check for the existence of a file:
if (open(filename,”r”,1)) file_exists;
else file_does_not_exist;
The return value F is an IOStream (or just stream for short). When
the last reference to this return value is discarded, the file will
be closed. The file can also be explicitly closed with the close
function. The FILEMODE determines whether the file is to be
opened in read, write, or update mode, and whether writes are
restricted to the end-of-file (append mode). FILEMODE also
determines whether the file is opened as a text file or as a
binary file. FILEMODE can have the following values, which are
the same as for the ANSI standard fopen function:
“r” – read only
“w” – write only, random access, existing file overwritten
“a” – write only, forced to end-of-file,
existing file preserved
“r+” – read/write, random access, existing file preserved
“w+” – read/write, random access, existing file overwritten
“a+” – read/write, reads random access,
writes forced to end-of-file, existing file preserved