edt_os_utils.h File Reference

(git e241c21fae, 2024-09-04)

#include "edt_types.h"
#include "edt_portability.h"

Functions
double	edt_dtime (void)
	Return the time in seconds since the last call to edt_dtime. More...
double	edt_timestamp (void)
	Gets the seconds + fractional seconds since the Epoch, OS independent. Uses system time; accuracy is OS dependent. More...
void	edt_msleep (int msecs)
	Causes the process to sleep for the specified number of milliseconds. More...
void	edt_usleep (int usecs)
	Causes process to sleep for specified number of microseconds. More...
void	edt_free (void *ptr)
	Convenience routine to free the memory allocated with edt_alloc. More...
void *	edt_alloc (size_t size)
	Convenience routine to allocate memory in a system-independent way. The buffer returned is page aligned. Uses VirtualAlloc on Windows NT systems, posix_memalign on UNIX-based systems. More...
void	edt_closedir (DIRHANDLE h)
	Cross platform function to close a directory handle. More...
DIRHANDLE	edt_opendir (const char *dirname)
	Cross platform function to open a directory for reading. More...
int	edt_readdir (DIRHANDLE h, char *name)
	Cross platform function to read the next directory entry. More...
void	edt_correct_slashes (char *str)
	Change the slashes in str from forward to back or vice versa depending on whether it's Windows or Unix. More...
void	edt_fwd_to_back (char *str)
void	edt_back_to_fwd (char *str)
int	edt_access (const char *fname, int perm)
	Determines file access, independent of operating system. More...

Detailed Description

Copyright

Copyright (C) 2011 Engineering Design Team, Inc.

Utility functions with OS-specific implementations.

Function Documentation

edt_dtime()

double edt_dtime

(

void

)

Return the time in seconds since the last call to edt_dtime.

Each time edt_dtime is called, it returns the time delta since the last time it was called. Therefore the first time edt_dtime is called in a process the delta may be meaningless. Time is in seconds and fractions of a second.

This call uses system time, which is system dependent and may be too coarse for some applications. For more accurate time stamping consider the IRIG option and an external IRIG timestamp source, available with some EDT boards.

Returns

delta time, as a double floating point

edt_timestamp()

double edt_timestamp

(

void

)

Gets the seconds + fractional seconds since the Epoch, OS independent. Uses system time; accuracy is OS dependent.

Returns

The timestamp in seconds; a double value with tenths/hundredths/etc on the right of the decimal point.

edt_msleep()

void edt_msleep

(

int

msecs

)

Causes the process to sleep for the specified number of milliseconds.

Parameters

msecs

The number of milliseconds for the process to sleep.

Returns

0 on success, -1 on failure. If an error occurs, call #edt_perror to get the system error message.

edt_usleep()

void edt_usleep

(

int

usecs

)

Causes process to sleep for specified number of microseconds.

Parameters

usecs

Number of microseconds for process to sleep.

Returns

0 on success; -1 on error

edt_free()

void edt_free

(

void *

ptr

)

Convenience routine to free the memory allocated with edt_alloc.

Parameters

ptr	Address of memory buffer to free.

edt_alloc()

void * edt_alloc

(

size_t

size

)

Convenience routine to allocate memory in a system-independent way. The buffer returned is page aligned. Uses VirtualAlloc on Windows NT systems, posix_memalign on UNIX-based systems.

Parameters

size	Number of bytes of memory to allocate.

Returns

The address of the allocated memory, or NULL on error. If NULL, use #edt_perror to print the error.

edt_closedir()

void edt_closedir

(

DIRHANDLE

h

)

Cross platform function to close a directory handle.

Parameters

h	Open directory handle.

edt_opendir()

DIRHANDLE edt_opendir

(

const char *

dirname

)

Cross platform function to open a directory for reading.

Parameters

dirname

The name of the directory to open.

Returns

Directory handle upon success or NULL on failure.

edt_readdir()

int edt_readdir	(	DIRHANDLE	h,
		char *	name
	)

Cross platform function to read the next directory entry.

Parameters

h	A handle for the directory, returned by edt_opendir.
name	A pointer to a string into which the name of the next file in the directory will be written. The string must be allocated by the caller to at least 256 bytes.

Returns

h if entries remain or NULL if this is the last entry.

edt_correct_slashes()

void edt_correct_slashes

(

char *

str

)

Change the slashes in str from forward to back or vice versa depending on whether it's Windows or Unix.

Parameters

str	String to process.

edt_fwd_to_back()

void edt_fwd_to_back

(

char *

str

)

fwd_to_back: for use by edt_correct_slashes

edt_back_to_fwd()

void edt_back_to_fwd

(

char *

str

)

back_to_fwd: for use by edt_correct_slashes

edt_access()

int edt_access	(	const char *	fname,
		int	perm
	)

Determines file access, independent of operating system.

This a convenience routine that maps to access() on Unix/Linux systems and _access() on Windows systems.

Parameters

fname	Path name of file to check access permissions.
perm	Permission flag(s) to test for. See documentation for access() (Unix/Linux) or _access() (Windows) for valid values.

Returns

0 on success, -1 on failure

Example:

if(edt_access("file.ras", F_OK))
    printf("Warning: overwriting file %s\n", "file.ras");