Difference: CodingDataReconnaissance ( vs. 1)

Revision 12010-01-05 - DickFurnas

Line: 1 to 1
META TOPICPARENT name="CodingData"

Reconnaissance of Coding Data

These commands were used to perform basic integrity checks on the data, especially the first column, which is the most heterogeneous in the type of data it contains.
Table of Contents

Some command line stuff to perform basic integrity checks on the data.

Scale of stuff to look at

pbpaste | cat | wc
   65536    9807  101150
  • pbpaste takes the contents of the clipboard and sends it to stdout
  • | pipe character which "pipes" stdout to stdin of the following command
  • cat concatenates to stdout . I use cat here defensively: cat seems to do some smart things with encodings, "conditioning" the text for use by other utilities and in this simple pipeline could have been omitted with identical results. I have encountered situations in which subsequent processing of the clipboard contents behaved better when using pbpaste if I inserted cat . It may be superfluous voodoo smile
  • wc performs a word count, reporting number of lines, number of words, number of characters * The clipboard apparently has
    • 65536 lines -- more than I want to look at smile -- Most are probably empty. That number is 2^16 and probably represents the maximum number of possible rows.
    • 9807 words
    • 101150 characters

Scale of unique stuff

pbpaste | cat | sort | uniq -c | wc
     967    2571   14253
  • sort sorts the lines
  • uniq -c finds unique lines, the -c flag says to count how many instances of each line occurred
  • I was actually wanting to see the unique lines, but by starting with wc I got an idea of how much stuff I was going to need to look at, here nearly 1000 lines.

The unique stuff

pbpaste | cat | sort | uniq -c | less
  • same as above except replace wc with less which lets me page backwards and forwards through the output.

The unique stuff of likely interest that isn't a problem number

pbpaste | cat | grep '^[A-Z]' | sort | uniq -c | less
  • similar to above, but only show lines which start with a capital letter
  • grep g eneralized   r egular   e xpression   p arser looks at lines and passes ones which match to stdout discarding non-matches
    • ^ anchors to the start of the line
    • [A-Z] matches any single character in the given range
    • single quotes to protect the search pattern from interpretation by the shell

Check the other stuff

pbpaste | cat | grep -v '^[A-Z]' | sort | uniq -c | less
  • same as above, except the -v flag tells grep to reverse its behavior, send lines which do not match to stdout
  • Why? To see if I missed anything of interest.

-- DickFurnas - 2010-01-05

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