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Full Discussion: Newline in ANSI-C standard functions
Top Forums Programming Newline in ANSI-C standard functions Post 303020299 by yifangt on Monday 16th of July 2018 11:49:35 AM
Old 07-16-2018
Thanks Jim and Corona:
I was not sure the NULL terminator was handled correctly.
If str1 precedes str2 in memory and each one is word-aligned, then the last character you write to str1[128] effectively cause the end of of str1 to be the actual end of str2. This is quite twisting to me!! Now my understanding come to this:

1) Doing strncpy() first caused no NUL terminator, and gave me buffer overflow and strcpy() could not run at all.
2) Instead, doing strcpy() first the correct NUL terminator is ensured, then the following strncpy() seems working which still does not provide NUL terminator. But, because the program exits, just the problem did not show up.

Is this correct?
Blindly using strncpy because people call strcpy "bad" is worse than just using strcpy in the first place.

I do not know the risk of strcpy() or the correct use of strncpy(). They just happened to come to my exercise. I thought figure out the details may help understanding what's going on in the memory, which is why I tried memset(). Thanks again.
Last edited by yifangt; 07-16-2018 at 01:06 PM..
 

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LEARN ABOUT DEBIAN

ansi_code

term::ansi::code(3tcl)						 Terminal control					    term::ansi::code(3tcl)

__________________________________________________________________________________________________________________________________________________

NAME

       term::ansi::code - Helper for control sequences

SYNOPSIS

       package require Tcl  8.4

       package require term::ansi::code  ?0.1?

       ::term::ansi::code::esc str

       ::term::ansi::code::escb str

       ::term::ansi::code::define name escape code

       ::term::ansi::code::const name code

_________________________________________________________________

DESCRIPTION

       This package provides commands enabling the definition of control sequences in an easy manner.

       ::term::ansi::code::esc str
	      This command returns the argument string, prefixed with the ANSI escape character, "33."

       ::term::ansi::code::escb str
	      This command returns the argument string, prefixed with a common ANSI escape sequence, "33[".

       ::term::ansi::code::define name escape code
	      This  command defines a procedure name which returns the control sequence code, beginning with the specified escape sequence, either
	      esc, or escb.

       ::term::ansi::code::const name code
	      This command defines a procedure name which returns the control sequence code.

BUGS, IDEAS, FEEDBACK
       This document, and the package it describes, will undoubtedly contain bugs and other problems.  Please report such in the category term	of
       the  Tcllib  SF	Trackers [http://sourceforge.net/tracker/?group_id=12883].  Please also report any ideas for enhancements you may have for
       either package and/or documentation.

KEYWORDS

       control, declare, define, terminal

CATEGORY

       Terminal control

COPYRIGHT

       Copyright (c) 2006 Andreas Kupries <andreas_kupries@users.sourceforge.net>

term									0.1						    term::ansi::code(3tcl)
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