Ascii value of character? - Page 2 - UNIX for Dummies Questions & Answers

sszd · #8 09-10-2008

Quote:

Originally Posted by Ygor

Interesting. From info printf...

Quote:

* If the leading character of a numeric argument is `"' or `'' then
its value is the numeric value of the immediately following
character. Any remaining characters are silently ignored if the
`POSIXLY_CORRECT' environment variable is set; otherwise, a
warning is printed. For example, `printf "%d" "'a"' outputs `97'
on hosts that use the ASCII character set, since `a' has the
numeric value 97 in ASCII.

Quote:

Originally Posted by fpmurphy

From POSIX.1-2001 ..

Quote:

The argument operands will be treated as strings if the corresponding conversion character is b, c or s; otherwise, it will be evaluated as a C constant, as described by the ISO C standard, with the following extensions:

* If the leading character is a single- or double-quote, the value will be the numeric value in the underlying codeset of the character following the single- or double-quote.

Both of these seem to answer my question. None of the man pages (on Solaris 10) explained this with this kind of detail. Thank you.

shamrock · #9 09-10-2008

Quote:

If the leading character of a numeric argument is `"' or `'' then
its value is the numeric value of the immediately following
character. Any remaining characters are silently ignored if the
`POSIXLY_CORRECT' environment variable is set; otherwise, a
warning is printed. For example, `printf "%d" "'a"' outputs `97'
on hosts that use the ASCII character set, since `a' has the
numeric value 97 in ASCII.

The printf() manpage on AIX doesn't have this information. The flip side is whether printf() checks for the terminating single-tick to ensure that it's a character. On AIX something like this outputs the decimal value of 'A' in the ASCII character code alongwith an error message. So just for grins what would be its output on your machine???

Code:

printf "%d\n" "'AB"
printf: 3016-002 'AB is not completely converted.
65

sszd · #10 09-10-2008

Quote:

Originally Posted by shamrock

Code:

printf "%d\n" "'AB"
printf: 3016-002 'AB is not completely converted.
65

Virtually identical to yours...

Code:

printf "%d\n" "'AB"
printf: 'AB not completely converted
65

sszd · #11 09-10-2008

Actually, I just found this out.

In csh and ksh the output is as I've shown above. However, in bash it's this...

Code:

printf "%d\n" "'AB"
65

era · #12 09-10-2008

If Perl is acceptable, it offers the ord() function for returning the character code of a single character. When invoked on a multi-character string, it simply returns the character code of the first character of the string.

Code:

perl -le 'print ord(shift)' A

shamrock · #13 09-10-2008

Quote:

Originally Posted by sszd

Actually, I just found this out.

In csh and ksh the output is as I've shown above. However, in bash it's this...

Code:

printf "%d\n" "'AB"
65

On HP-UX it outputs the ASCII value of the character but no errors that is the same as in bash for the o/p.

Code:

printf "%d\n" "'AB"
65

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