Re: Whaddaya think?

From	Ben Bacarisse <ben@bsb.me.uk>
Newsgroups	comp.lang.c
Subject	Re: Whaddaya think?
Date	2024-06-16 10:30 +0100
Organization	A noiseless patient Spider
Message-ID	<87h6dtw7y4.fsf@bsb.me.uk> (permalink)
References	<666ded36$0$958$882e4bbb@reader.netnews.com> <87sexdx3s1.fsf@bsb.me.uk> <v4l7np$3m349$2@dont-email.me>

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bart <bc@freeuk.com> writes:

> On 15/06/2024 23:03, Ben Bacarisse wrote:
>> DFS <nospam@dfs.com> writes:
>> 
>>> I want to read numbers in from a file, say:
>>>
>>> 47 185 99 74 202 118 78 203 264 207 19 17 34 167 148 54 297 271 118 245 294
>>> 188 140 134 251 188 236 160 48 189 228 94 74 27 168 275 144 245 178 108 152
>>> 197 125 185 63 272 239 60 242 56 4 235 244 144 69 195 32 4 54 79 193 282
>>> 173 267 8 40 241 152 285 119 259 136 15 83 21 78 55 259 137 297 15 141 232
>>> 259 285 300 153 16 4 207 95 197 188 267 164 195 7 104 47 291
>>>
>>>
>>> This code:
>>> 1 opens the file
>>> 2 fscanf thru the file to count the number of data points
>>> 3 allocate memory
>>> 4 rewind and fscanf again to add the data to the int array
>>>
>>> Any issues with this method?
>> There are two issues: (1) you end up with a program that can't be
>> "piped" to (because the input can't be rewound), and (2) the file might
>> change between counting and reading.
>
> It might change even while you're reading it once.

Your program will see the data it sees -- in that sense the file does
not change.  When there are two (or more) phases to the input, your
program has to handle some new error conditions that are logically
avoided by just reading what's available (even if, to some outside
observer, it's "changing").

-- 
Ben.

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Whaddaya think? DFS <nospam@dfs.com> - 2024-06-15 15:36 -0400
  Re: Whaddaya think? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-06-15 22:33 +0100
  Re: Whaddaya think? Ben Bacarisse <ben@bsb.me.uk> - 2024-06-15 23:03 +0100
    Re: Whaddaya think? bart <bc@freeuk.com> - 2024-06-16 00:22 +0100
      Re: Whaddaya think? Ben Bacarisse <ben@bsb.me.uk> - 2024-06-16 10:30 +0100
    Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-16 11:52 -0400
      Re: Whaddaya think? Ben Bacarisse <ben@bsb.me.uk> - 2024-06-17 00:17 +0100
        Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-17 08:49 -0400
  Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-15 15:22 -0700
    Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-16 12:20 -0400
      Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-16 13:54 -0700
      Re: Whaddaya think? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-16 22:41 -0400
        Re: Whaddaya think? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-16 22:45 -0700
        Re: Whaddaya think? Kaz Kylheku <643-408-1753@kylheku.com> - 2024-06-17 07:39 +0000
          Re: Whaddaya think? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-06-17 01:22 -0700
          Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-17 09:50 -0400
            Re: Whaddaya think? Richard Harnden <richard.nospam@gmail.invalid> - 2024-06-17 16:23 +0100
              Re: Whaddaya think? David Brown <david.brown@hesbynett.no> - 2024-06-17 18:46 +0200
              Re: Whaddaya think? Kaz Kylheku <643-408-1753@kylheku.com> - 2024-06-22 22:14 +0000
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-22 17:10 -0700
                Re: Whaddaya think? Phil Carmody <pc+usenet@asdf.org> - 2024-06-23 11:20 +0300
          Re: Whaddaya think? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-18 00:19 -0700
            Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-18 03:10 -0700
              Re: Whaddaya think? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-18 17:24 -0700
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-18 17:55 -0700
                Re: Whaddaya think? Kaz Kylheku <643-408-1753@kylheku.com> - 2024-06-19 01:58 +0000
        Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-17 08:50 -0400
          Re: Whaddaya think? Ben Bacarisse <ben@bsb.me.uk> - 2024-06-17 15:41 +0100
            Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-18 08:12 +0200
              Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-18 03:07 -0700
      Re: Whaddaya think? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-17 00:30 -0400
  Re: Whaddaya think? Michael S <already5chosen@yahoo.com> - 2024-06-16 01:56 +0300
    Re: Whaddaya think? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-06-16 03:26 +0000
      Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 05:41 +0200
        Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-15 21:17 -0700
          Re: Whaddaya think? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-06-16 04:41 +0000
          Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 06:44 +0200
            Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-16 11:09 -0400
              Re: Whaddaya think? David Brown <david.brown@hesbynett.no> - 2024-06-16 17:56 +0200
                Re: Whaddaya think? bart <bc@freeuk.com> - 2024-06-16 18:14 +0100
                Re: Whaddaya think? David Brown <david.brown@hesbynett.no> - 2024-06-17 14:44 +0200
                Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-17 09:52 -0400
        Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 06:51 +0200
          Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-15 22:21 -0700
            Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 07:41 +0200
              Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-15 22:49 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 11:29 +0200
                Re: Whaddaya think? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-06-16 16:04 +0100
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 17:13 +0200
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-16 13:32 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-17 07:41 +0200
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-16 23:20 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-17 09:16 +0200
                Re: Whaddaya think? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-17 09:38 -0400
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-17 16:17 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-18 07:09 +0200
                Re: Whaddaya think? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-18 03:25 -0400
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-18 02:57 -0700
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-17 16:15 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-18 08:02 +0200
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-18 19:07 -0700
                Re: Whaddaya think? David Brown <david.brown@hesbynett.no> - 2024-06-19 09:50 +0200
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-19 13:13 -0700
                Re: Whaddaya think? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-17 02:21 -0400
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-17 09:22 +0200
              Re: Whaddaya think? Michael S <already5chosen@yahoo.com> - 2024-06-16 11:11 +0300
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 11:07 +0200
                Re: Whaddaya think? Michael S <already5chosen@yahoo.com> - 2024-06-16 12:38 +0300
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 12:03 +0200
                Re: Whaddaya think? Michael S <already5chosen@yahoo.com> - 2024-06-16 14:31 +0300
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 17:37 +0200
                Re: Whaddaya think? Michael S <already5chosen@yahoo.com> - 2024-06-17 00:45 +0300
              Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-16 17:06 -0700
                Re: Whaddaya think? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-16 22:40 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-17 07:52 +0200
                Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-17 09:45 -0400
                Re: Whaddaya think? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-06-17 13:16 -0700
                Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-17 17:07 -0400
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-17 15:48 -0700
                Re: Whaddaya think? scott@slp53.sl.home (Scott Lurndal) - 2024-06-17 22:48 +0000
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-17 15:44 -0700
                Re: Whaddaya think? David Brown <david.brown@hesbynett.no> - 2024-06-18 15:00 +0200
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-18 06:57 +0200
                Re: Whaddaya think? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-18 00:25 -0700
                Re: Whaddaya think? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-17 02:38 -0400
                Re: Whaddaya think? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-18 17:01 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-17 07:48 +0200
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-16 23:29 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-17 09:35 +0200
        Re: Whaddaya think? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-06-16 08:19 +0100
        Re: Whaddaya think? Michael S <already5chosen@yahoo.com> - 2024-06-16 10:44 +0300
          Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 11:13 +0200
    Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-16 11:03 -0400
  Re: Whaddaya think? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2024-06-16 15:52 +0000
    Re: Whaddaya think? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-06-16 17:17 +0100
    Re: Whaddaya think? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-06-18 08:06 +0000

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