Tcl open file write

Truncate it if it exists. If it does not exist, create a new file. If the file does not exist, create a new empty file. Set the file pointer to the end of the file prior to each write.

Set the initial access position to the end of the file. Alternatively, you could rewrite your code so that the file is opened only once, outside the loop: set outfile1 [open "report1. Eric Melski Eric Melski You should upvote and accept the answer to indicate that it solved your problem!

I have one more question. Will appreciate if on can answer. Maybe you can start a new question with additional details, rather than using comments this way. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Opens an existing text file for reading purpose and the file must exist.

This is the default mode used when no accessMode is specified. Opens a text file for writing, if it does not exist, then a new file is created else existing file is truncated.

Opens a text file for writing in appending mode and file must exist. Here, your program will start appending content in the existing file content. Opens a text file for reading and writing both. Newcomers often try to write this with eof , and generally confuse themselves in the process [ L1 ]. It calls for. See also :: fileutil ::foreachLine , which does roughly the same thing.

I just noticed that there isn't an example of writing a file, so here goes: note: When you are writing into a file , the contents of the file will not be visible till the end of the execution of the TCL script.

Its contents are visible only after the file has finished executing. LV Of course, if there is a need to see the file while it is open, just be certain your code invokes flush , which will force the output to the file instead of waiting until there is a large enough chunk of data to force out. A simple tk example using the text widget is at Text Widget Example. But a file without newline at end of last line is not considered too well-behaved. Since in this example, a plain string is puts 'ed, I'd advocate a newline here.

It's different when you save a text widget's content, where a newline after the last line is always guaranteed; there the -nonewline switch is well in place. About the extra newline thing This is the proper behavior, even if it isn't technically required for most things these days. Unix text editors and tools still enforce it, however. Should it be considered a bug if Tcl behaves this way under Win32? LV This comment puzzles me. I have never seen a requirement for text files to end in blank lines.

I have seen a few broken programs which generated an error if the last line in a file didn't end in a newline - but that doesn't create a blank line.

And I don't understand the last question - if Tcl behaves which way under Win32? In situations where output is line buffered default for text , puts -nonewline does not immediately deliver the output. Andreas Kupries. This scheme hides implementation details and therefore allows modifying of file-handling at run-time by adjusting with-open-file. More about this at Emulating closures in Tcl page.

Anyone have the know-how to add to this page to cover reading and writing binary data and data from various languages ie interacting with the encoding system? RS : If the encoding is known, just add the command. See also Unicode file reader , A little Unicode editor. AK : Regarding the other part of the question see Working with binary data.