dtmsglogopenfile(3) [hpux man page]

DtMsgLogOpenFile(library call)											    DtMsgLogOpenFile(library call)

NAME

       DtMsgLogOpenFile -- opens a log file

SYNOPSIS

       #include <Dt/MsgLog.h>
       FILE* DtMsgLogOpenFile(
       const char* type,
       char** filename_return);

DESCRIPTION

       The DtMsgLogOpenFile function calls fopen to open a log file with type open mode. If fopen opens a log file successfully and returns a non-
       NULL filename_return, DtMsgLogOpenFile calls malloc to allocate space for filename_return.  DtMsgLogOpenFile then copies the log file  name
       to filename_return.

       The caller must use the free function to release the space allocated for filename_return, if it is not NULL. The caller must also close the
       file pointer returned by DtMsgLogOpenFile. Use caution in doing this because stderr may be returned.

       For a description of the algorithm used to determine the log file to open, see DtMsgLogMessage(3). Note	that  if  a  log  file	cannot	be
       opened, filename_return will be set to NULL.

ARGUMENTS

       type	 Specifies the file open flag. See fopen(3) for more information.

       filename_return
		 Specifies the variable to receive the returned log file name.

ENVIRONMENT VARIABLES

       None.

RESOURCES

       None.

ACTIONS
/MESSAGES
       None.

ERRORS
/WARNINGS
       None.

EXAMPLES

       The following code fragment opens the log file, logs the log file name, closes the file, and frees the space allocated for the file name.

       char * log_file;
       FILE * fp = DtMsgLogOpenFile ("a+", &log_file);

       if (log_file) {
	   DtMsgLogMessage (argv[0], DtMsgLogInformation,
		 "The log file name is: %s", log_file);
	   free (log_file);
       }
       if (fp && fp != stderr)
	    fclose (fp);

RETURN VALUE

       If DtMsgLogMessage completes successfully, it returns a pointer to the opened log file.	If it cannot open a log file, it returns stderr.

FILES

       None.

SEE ALSO

       DtMsgLogMessage(3), DtMsgLogSetHandler(3)

														    DtMsgLogOpenFile(library call)

fopen(3UCB)					     SunOS/BSD Compatibility Library Functions					       fopen(3UCB)

NAME

       fopen, freopen - open a stream

SYNOPSIS

       /usr/ucb/cc[ flag ... ] file ...
       #include <stdio.h>

       FILE *fopen( file,  mode);
       const char *file, *mode;

       FILE *freopen(file, mode, iop);
       const char *file, *mode;
       register FILE *iop;

DESCRIPTION

       The  fopen()  function opens the file specified by file and associates a stream with it. If the open succeeds, fopen() returns a pointer to
       be used to identify the stream in subsequent operations. The file argument points to a character string that contains the name of the  file
       to be opened. The mode argument is a character string having one of the following values:

       r	open for reading

       w	truncate or create for writing

       a	append: open for writing at end of file, or create for writing

       r+	open for update (reading and writing)

       w+	truncate or create for update

       a+	append; open or create for update at EOF

       The freopen() function opens the file specified by file and associates the stream pointed to by iop with it. The mode argument is used just
       as in fopen(). The original stream is closed, regardless of whether the open ultimately succeeds. If the open succeeds,	freopen()  returns
       the original value of iop.

       The freopen() function is typically used to attach the preopened streams associated withstdin, stdout, and stderr to other files.

       When  a	file  is  opened for update, both input and output can be performed on the resulting stream. Output cannot be directly followed by
       input without an intervening fseek(3C) or rewind(3C). Input cannot be directly followed by  output  without  an	intervening  fseek(3C)	or
       rewind(3C). An input operation that encounters  EOF will fail.

RETURN VALUES

       The fopen() and freopen() functions return a NULL pointer on failure.

USAGE

       The fopen() and freopen() functions have transitional interfaces for 64-bit file offsets.  See lf64(5).

SEE ALSO

       open(2), fclose(3C), fopen(3C), freopen(3C), fseek(3C), malloc(3C), rewind(3C), lf64(5)

NOTES

       Use  of	these  functions  should  be  restricted  to applications written on BSD platforms.  Use of these functions with any of the system
       libraries or in multithreaded applications is unsupported.

       To support the same number of open files as the system, fopen() must allocate additional memory for data structures using malloc(3C)  after
       64 files have been opened.  This confuses some programs that use their own memory allocators.

       The  fopen()  and  freopen() functions differ from the standard I/O functions fopen(3C) and freopen(3C). The standard I/O functions distin-
       guish binary from text files with an additional use of 'b' as part of the mode, enabling portability of fopen(3C)  and  freopen(3C)  beyond
       SunOS  4.x systems.

SunOS 5.10							    22 Jan 1993 						       fopen(3UCB)