The following sections describe stream I/O requirements for using:
Within the C or C++ run-time environment, stream I/O for files up to two GB in size is enabled by specifying the *IFSIO option on the system interface keyword (SYSIFCOPT) on the Create Module or Create Bound Program command prompt.
When using the SYSIFCOPT keyword with either command, follow this format:
CRTCPPMOD MODULE(QTEMP/IFSIO) SRCFILE(QCPPLE/QACSRC) SYSIFCOPT(*IFSIO)
CRTBNDCPP PGM(QTEMP/IFSIO) SRCFILE(QCPPLE/QACSRC) SYSIFCOPT(*IFSIO)
When the *IFSIO option is specified, the compiler defines the __IFS_IO__ macro. When __IFS_IO__ is defined, prototypes associated with stream I/O in <stdio.h> are no longer defined. The header file <ifs.h> is included by <stdio.h>, which declares all structure and prototypes associated with the integrated file system enabled C stream I/O.
The 64-bit version of the Integrated File System interface lets you use
ILE C stream I/O with files up to and greater than two gigabytes in
size. (C++ stream I/O for files greater than two gigabytes is not
supported.) To enable the 64-bit interface, specify the *IFS64IO option
with the SYSIFCOPT keyword on the CRTCPPMOD or CRTBNDCPP command
prompt. When this option is specified, the compiler defines the
__IFS64_IO__ macro which, for example, remaps the
open() function to an open64() function to allow 64-bit
indexing..

The fstream(), ifstream(), and ofstream()
classes have a new open mode ios::text, which opens the
file in text mode.
By default, I/O streams are opened in binary mode (not in text mode, as stated in the Version 3 Release 7 books).
If the input or output is formatted (via the >> or << operator), newline
(\n) characters are not expanded to \r\n on
output but any \r characters are stripped out on input
If you want to add carriage return (\r) characters, use the fopen() function with crln=Y (the default).
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