Syntax

assert(T)

assert(T, msg)

Arguments

Name

Description

T

A Boolean.

msg

A string.  An error returned if T is false.  If it is missing, it defaults to "assertion failed!"

Example

Syntax

assert(true)

assert(false)

assert(1 == 1)

assert(1 == 0, 'my error')

Comments

assert(T) returns an error if met is false.

See Also:

pcall

folder

A string of the folder name.  Folders must be separated by a forward slash (/) or (\\).

folder

A string of the folder name.  Folders must be separated by a forward slash (/) or (\\).

Syntax

copyfile(source_file, destination_file)

Argument

Name

Description

source_file

A string: a file or a directory name to copy.

destination_file

A string: a file or a directory name as the destination.

If the source is a directory, the destination need to be a directory.

Outputs

Name

Description

See Also

Remove

Rename

unix

Returns an approximation of the amount (in seconds) of CPU time used by the application on the Windows operating system. On Linux, the time is the total execution time of the last command or scripts.

Returns the date and time in a string.

Returns the number of seconds from time t1 to time t2.  The two time variables are assumed to be in seconds.

folder

A string of the directory name. Directories must be separated by a forward slash, (/).

match        

A matching string to limit the listing information to. It can include the wildcard character ‘*’.

Syntax

error(str)

Arguments

Name

Description

str

A string: the error message to return.

Example

Syntax

function foo(n)

  if n < 0 then

   error('a positive value expected.')

  end

  return n * n;

end

 foo(-1)

 foo(2)

Result

// foo(-1)

[string " function foo(n)..."]:3: a positive value expected.

Comments

The error function stops the current script execution and displays an error message.

See Also:

assert

pcall

Syntax

exit()

Example

Syntax

// WARNING : it will close this session

exit()

Comments

exit() ends the current HyperMath session.

Syntax

path_f, file_f, ext_f = fileparts(filename)

Argument

Name

Description

filename

A string of a file or a directory.

Outputs

Name

Description

path_f

A string: the path.

file_f

A string: the filename.

ext_f

A string: the extension.

Example

Syntax

print(fileparts('c:/Windows'))

pathf, namef, extf = fileparts('c:\\dir\\file.ext')

print(pathf, namef, extf)

Comments

path_f, file_f, ext_f = fileparts(filename) splits filename into three parts: path, filename and its extension (including '.').

fileparts only parses the input string and performs no existence checks.

See Also:

isdir

isfile

separator

An optional string used as a directory separator in the output. The default is a forward slash, (/).

var

A string of the environment variable name.  Returns nil if variable is not defined.

The following gets the system variable value ALTAIR_HOME.

GetEnvVar("ALTAIR_HOME")

Syntax

id = getpid()

Outputs

Name

Description

id

A number.

Example

Syntax

print(getpid())

See Also:

memory

Syntax

p = getuserdir()

Outputs

Name

Description

p

A string: the path of the user home directory.

Example

Syntax

print(getuserdir())

See Also:

cd

Syntax

R = isdir(A)

Argument

Name

Description

A

A string.

Outputs

Name

Description

R

0 (false) or 1 (true) if the string is an existing path.

Example

Syntax

print(isdir('/'))

print(isdir('c:/'))

print(isdir('c:/Windows'))

Comments

R = isdir(A) returns logical 1 (true) if A is a valid folder.

It returns logical 0 (false) otherwise.

See Also:

isfile

Syntax

R = isfile(A)

Argument

Name

Description

A

A string.  A filename.

Outputs

Name

Description

R

0 (false) or 1 (true) if the string is an existing filename.

Example

Syntax

print(isfile('c:/Windows'))

Comments

R = isfile(A) returns logical 1 (true) if A is an existing filename.

It returns logical 0 (false) if the file does not exist.

See Also:

isdir

Syntax

total_mem_used, total_mem_available, mem_used_by_hypermath = memory()

Argument

Name

Description

total_mem_used

Total physical memory used (kilobytes).

total_mem_available

Total physical memory available (kilobytes).

mem_used_by_hypermath

Memory used by HyperMath in the current session (kilobytes).

Example

Syntax

total_mem_used, total_mem_available, mem_used_by_hypermath_1 = memory();

print('Memory used by Hypermath:', mem_used_by_hypermath_1/1024, ' MB');

M = ones(9000,9000);

total_mem_used, total_mem_available, mem_used_by_hypermath_2 = memory();

print('Memory used by Hypermath:', mem_used_by_hypermath_2/1024, ' MB');

Clear('M');

total_mem_used, total_mem_available, mem_used_by_hypermath_3 = memory();

print('Memory used by Hypermath:', mem_used_by_hypermath_3/1024, ' MB');

print('Physical memory on your system: ', total_mem_available/1024, ' MB');

folder

A string of the folder name.  Folders must be separated by a forward slash (/) or (\\).

Syntax

p = pwd()

p = pwd(sep)

Argument

Name

Description

sep

A string: '/' or '\\'.  An optional string used as a directory separator in the output.

Outputs

Name

Description

p

A string: the current path.

Example

Syntax

print(pwd())

print(pwd('/'))

print(pwd('\\'))

Comments

p = pwd() returns a string containing the current working directory.

See Also:

Chdir

item

A string of the folder name.

Comments

To remove a directory, see Rmdir.

old

A string of the current file or folder name.  Folders must be separated by a forward slash (/) or (\\).

new

A string of the new file or folder name.  Folders must be separated by a forward slash (/) or (\\).

folder

A string of the folder name.  Folders must be separated by a forward slash (/).

s

Removes a folder which contains sub-folders.

expression

A string of the environment variable setting command.  Spaces should not precede the equal sign.

The following sets the system variable value TEST to This Is A test.

SetEnvVar("TEST= This Is A Test")

command

Any system command as a string. Folders must be separated by a forward or backward slash, (/) or (\\).

The following executes the system command to set the time.

System("time")

Syntax

t = Time()

Argument

Name

Description

t

A number: current time since the Epoch (seconds).

Example

Syntax

t1 = Time();

print(t1);

sleep(10);

t2 = Time();

print(t2)

print('t2 - t1 = ', t2 - t1)

Comments

t = Time() returns the current time in seconds since the Epoch.