_READFILE$

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The _READFILE$ function returns the complete contents of a file in a single string, but without the usual overhead. It does OPEN, GET and CLOSE the file in one run.


Syntax

contents$ = _READFILE$(fileSpec$)


Parameters

  • contents$ is the entire file contents returned as STRING. May return an empty string, if the specified file was empty, or if the program was continued from a file related ERROR.
  • fileSpec$ is the name of the file to read as literal or variable STRING, if required inclusive a full or relative path.
    • To avoid errors you should use _FILEEXISTS before calling this function to make sure the file exists.


Description

  • Sometimes it's required or at least useful to have the whole contents of a file in a single string for further processing, e.g. to pass it to hashing or compression functions which expect strings.
  • In earlier versions of QB64(PE) you had to implement that loading process manually all the time or create a reusable custom FUNCTION for it.
  • Now _READFILE$ will simplify this, it's mainly a convenience function to wrap the following code sequence into one handy function:
fh = FREEFILE
OPEN fileSpec$ FOR BINARY AS #fh
contents$ = SPACE$(LOF(fh))
GET #fh, , contents$
CLOSE #fh


Availability


Examples

Example 1
Showing that this function's result is equal to the code sequence shown above.
$COLOR:0

fileSpec$ = "source\global\settings.bas"

fh = FREEFILE
OPEN fileSpec$ FOR BINARY AS #fh
content$ = SPACE$(LOF(fh))
GET #fh, , content$
CLOSE #fh

COLOR LightGreen
PRINT "Using old manual load method..."
COLOR White
PRINT content$

COLOR LightGreen
PRINT "Using new direct load method..."
COLOR White
PRINT _READFILE$(fileSpec$)

END
Example by RhoSigma

Example 2
Passing a whole file's contents to hashing functions.
$COLOR:0

fileSpec$ = "source\global\settings.bas"

COLOR LightGreen
PRINT "CRC32 of the file..."
COLOR White
PRINT RIGHT$("00000000" + HEX$(_CRC32(_READFILE$(fileSpec$))), 8)
PRINT

COLOR LightGreen
PRINT "MD5 of the file..."
COLOR White
PRINT _MD5$(_READFILE$(fileSpec$))

END
Example by RhoSigma


See also



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