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Full Discussion: behaviour of read() and write() after a select()
Top Forums Programming behaviour of read() and write() after a select() Post 302242175 by calv on Wednesday 1st of October 2008 09:58:13 AM
Old 10-01-2008
Quote:
Originally Posted by Perderabo
If you select on a terminal and I am typing on it, select returns on the first character. If you then do a blocking read for 10 characters, you will block until I type nine more. I really can't imagine any alternative behavior.
I use read(), not fread(). read() could for example only return 1 byte. As all available docs say, that read() *can* return less bytes then requested. So the return value of the read() call in your case would be 1 (in my optinion). Then a program would decide to either
  1. Wait for the rest, by calling read() again, this time requesting the 9 bytes missing
  2. call select() again, to be notified, when you press your next key
 

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cut

CUT(1)                                                             User Commands                                                            CUT(1)

NAME

       cut - remove sections from each line of files

SYNOPSIS

       cut OPTION... [FILE]...

DESCRIPTION

       Print selected parts of lines from each FILE to standard output.

       With no FILE, or when FILE is -, read standard input.

       Mandatory arguments to long options are mandatory for short options too.

       -b, --bytes=LIST
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       -c, --characters=LIST
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       -d, --delimiter=DELIM
              use DELIM instead of TAB for field delimiter

       -f, --fields=LIST
              select only these fields;  also print any line that contains no delimiter character, unless the -s option is specified

       -n     (ignored)

       --complement
              complement the set of selected bytes, characters or fields

       -s, --only-delimited
              do not print lines not containing delimiters

       --output-delimiter=STRING
              use STRING as the output delimiter the default is to use the input delimiter

       -z, --zero-terminated
              line delimiter is NUL, not newline

       --help display this help and exit

       --version
              output version information and exit

       Use  one,  and only one of -b, -c or -f.  Each LIST is made up of one range, or many ranges separated by commas.  Selected input is written
       in the same order that it is read, and is written exactly once.  Each range is one of:

       N      N'th byte, character or field, counted from 1

       N-     from N'th byte, character or field, to end of line

       N-M    from N'th to M'th (included) byte, character or field

       -M     from first to M'th (included) byte, character or field

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