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.