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Re: strtok() and the mistery of the same address strings with different lengths...

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"Fernando D. Bozzo" <fdbozzo@gmail.com> writes:
> Ok, this is driving me crazy since 2 hours now.
[...]
> ...How is possible that the function strtok() could return different
> strings --each with it's own \0 termination-- in different string
> variables without dinamic memory?
[...]

strtok() modifies its input string in place.

The first time you call it with a non-NULL second argument, it remembers
the location of the string you're tokenizing.  (This is a real problem
if you want to tokenize two different strings concurrently.)

If you start with a string (showing the terminating '\0' explicitly)

    "abc def ghi\0"

and use strtok() to split it on ' ' delimiters, then after you're done
looping over it, the same memory will contain:

    "abc\0def\0ghi\0"

A pointer to the 'a', to the 'd', or to the 'g' will point to a valid
null-terminated string with a length of 3 characters.  The original
11-character string "abc def ghi" will have been clobbered.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

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strtok() and the mistery of the same address strings with different lengths... "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-13 16:16 -0800
  Re: strtok() and the mistery of the same address strings with different lengths... "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-13 16:30 -0800
  Re: strtok() and the mistery of the same address strings with different lengths... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-14 00:44 +0000
    Re: strtok() and the mistery of the same address strings with different lengths... "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-13 17:43 -0800
    Re: strtok() and the mistery of the same address strings with different lengths... Manfred <noname@invalid.add> - 2017-01-14 16:52 +0100
      Re: strtok() and the mistery of the same address strings with different lengths... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-14 19:38 +0000
  Re: strtok() and the mistery of the same address strings with different lengths... Keith Thompson <kst-u@mib.org> - 2017-01-13 16:49 -0800
    Re: strtok() and the mistery of the same address strings with different lengths... "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-13 17:39 -0800
      Re: strtok() and the mistery of the same address strings with different lengths... James Kuyper <jameskuyper@verizon.net> - 2017-01-13 22:00 -0500
        Re: strtok() and the mistery of the same address strings with different lengths... "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-14 03:11 -0800
          Re: strtok() and the mistery of the same address strings with different lengths... James Kuyper <jameskuyper@verizon.net> - 2017-01-14 10:50 -0500
            Re: strtok() and the mistery of the same address strings with different lengths... Keith Thompson <kst-u@mib.org> - 2017-01-14 14:27 -0800
              Re: strtok() and the mistery of the same address strings with different lengths... "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-14 15:21 -0800
              Re: strtok() and the mistery of the same address strings with different lengths... Les Cargill <lcargill99@comcast.com> - 2017-01-15 11:48 -0600
                Re: strtok() and the mistery of the same address strings with different lengths... Keith Thompson <kst-u@mib.org> - 2017-01-15 15:24 -0800
                Re: strtok() and the mistery of the same address strings with different lengths... Les Cargill <lcargill99@comcast.com> - 2017-01-15 22:11 -0600
      Re: strtok() and the mistery of the same address strings with different lengths... Manfred <noname@invalid.add> - 2017-01-14 16:48 +0100
  Re: strtok() and the mistery of the same address strings with different lengths... "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-14 03:18 -0800
    Re: strtok() and the mistery of the same address strings with different lengths... "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-14 04:16 -0800
      Re: strtok() and the mistery of the same address strings with different lengths... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-14 15:14 +0000
        Re: strtok() and the mistery of the same address strings with different lengths... "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-14 09:58 -0800
          Re: strtok() and the mistery of the same address strings with different lengths... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-14 19:51 +0000
            Re: strtok() and the mistery of the same address strings with different lengths... "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-14 15:18 -0800
        Re: strtok() and the mistery of the same address strings with different lengths... Keith Thompson <kst-u@mib.org> - 2017-01-14 14:17 -0800
    Re: strtok() and the mistery of the same address strings with different lengths... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-14 15:09 +0000
      Re: strtok() and the mistery of the same address strings with different lengths... "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-14 11:09 -0800
        Re: strtok() and the mistery of the same address strings with different lengths... luser droog <luser.droog@gmail.com> - 2017-01-14 11:41 -0800
        Re: strtok() and the mistery of the same address strings with different lengths... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-14 20:04 +0000
        Re: strtok() and the mistery of the same address strings with different lengths... James Kuyper <jameskuyper@verizon.net> - 2017-01-14 15:09 -0500
          Re: strtok() and the mistery of the same address strings with different lengths... "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-14 15:22 -0800
      Re: strtok() and the mistery of the same address strings with different lengths... Keith Thompson <kst-u@mib.org> - 2017-01-14 14:21 -0800

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