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# 22  
Old 08-26-2013
No international characters..just sequence data.
# 23  
Old 08-26-2013
Quote:
Originally Posted by alister
By the way, none of the OP's posts mention reading a fixed quantity
You need to check your reading comprehension. After his second post clarified, that was clearly the goal.
Quote:
(and none use the word byte ).
What else is a computer going to use, when reading bytes from a file? We're talking about programs and pipes -- not a unicode-aware text viewer. He'd have to go to special, extreme effort to not read in sizes of bytes.
# 24  
Old 08-26-2013
Quote:
Originally Posted by rajivn786
Thanks for the replies guys..
I have done bit of research & found that wc -m counts characters while wc -c counts the bytes..
Is byte a character in general in this context??? Because both give the same results.
If it is safe to assume that the source of your DNA sequence data (I presume that's what that is) will always generate single-byte characters, then -c will give the same result as -m.

If that's not a safe assumption, then you need to ask yourself a question: Do you care about counting the number of letters on each line or do you care about counting the number of bytes that are used to represent those letters? For the former, -m. For the latter, -c.

Regards,
Alister
# 25  
Old 08-26-2013
Quote:
Originally Posted by alister
If it is safe to assume that the source of your DNA sequence data (I presume that's what that is) will always generate single-byte characters, then -c will give the same result as -m.

If that's not a safe assumption, then you need to ask yourself a question: Do you care about counting the number of letters on each line or do you care about counting the number of bytes that are used to represent those letters? For the former, -m. For the latter, -c.

Regards,
Alister
Alister and Corona688,
Note that if you read a line into a shell variable and ask the shell for the length of the variable:
Code:
read x
echo ${#x}

the number printed will be the number of characters (not including the line terminating <newline> character); not the number of bytes.

And, if you're processing a file with a standards conforming implementation of awk:
Code:
awk '{printf("Line %d has length %d\n", NR, length($0))}' file

the numbers printed will again be the number of characters (not including the line terminating <newline> character); not the number of bytes.

Of course if you're using EBCDIC, ASCII, or one of the ISO 8859-* code sets, number of bytes is the same as number of characters.

Last edited by Don Cragun; 08-26-2013 at 06:26 PM.. Reason: Typo in ISO Standard codeset number.
 

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