Programmer Guide/Command Reference/WRITE: Difference between revisions

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  #file := [[Programmer_Guide/Shell_Items/File/NEW_FILE|new file]] * test.txt /Text /Write
  #file := [[Programmer_Guide/Shell_Items/File/NEW_FILE|new file]] * test.txt /Text /Write
  if '$#file[?]' != file || '$rc' != 0 then
  if '$#file[?]' != file || '$rc' != 0 [[Programmer_Guide/Macro_Library/StdLib#UM_and_EM|em]] $rc ; Cannot open file for writing
    em $rc ; Cannot open file for writing
    exit
end
   
   
  write /Newline /Format /- $#file 'this is %d format for %3.0f numbers' 1 0.2*10
  write /Newline /Format /- $#file 'this is %d format for %3.0f numbers' 1 0.2*10
  if '$rc' != 0 then
  if '$rc' != 0 [[Programmer_Guide/Macro_Library/StdLib#UM_and_EM|em]] $rc ; Cannot write to file.
    em $rc ; Cannot write to file.
    exit
end
   
   
  delete /Var #file
  delete /Var #file

Revision as of 15:12, 8 May 2014

WRITE file text [/Newline … /Newline]
WRITE file format args /Format [/Newline … /Newline]

WRITE [/Newline … /Newline] /- file text
WRITE  /Format [/Newline … /Newline] /- file format args

This STx command writes (hence its name) text to a file assigned to a file item. If no /Newline option is specified, the text of the next WRITE command will be placed in the same line. Format strings are described in Format Strings and Rules.

file
The name of a file item (must, obviously, be open for write access).
text
The output text (unformatted, written "as is"). Must not start with a slash, unless you are using the "end of options" option, /-.
format
The format string (see Format Strings and Rules). There must be a corresponding args argument for each "%" format tag in format because STx will not check if the number of arguments supplied matches the given format string and will, hence, crash heavily if there is any mistake. Must not start with a slash, unless you are using the "end of options" option, /-.
args
The arguments (one for each "%" format tag in format). Note that STx will not check if the number of arguments supplied matches the given format string and will, hence, crash heavily if there is any mistake. Furthermore, no argument must start with a slash, unless, of course, you are using the "end of options" option, /-.

Example

#f := $(new file * test.txt /T /W)
WRITE $#f 'this is %d format for %3.0f numbers' 1 0.2*10 /Newline /Format

The line "this is 1 format for 2 numbers" will be written to the file. Note that this is also an example of horribly bad programming style, not checking if the inline NEW FILE command succeeded, and happily executing garbage when it did not. A proper, clean alternative to the above code would be:

#file := new file * test.txt /Text /Write
if '$#file[?]' != file || '$rc' != 0 em $rc ; Cannot open file for writing

write /Newline /Format /- $#file 'this is %d format for %3.0f numbers' 1 0.2*10
if '$rc' != 0 em $rc ; Cannot write to file.

delete /Var #file

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