-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 According to Dave Korn on 4/21/2009 5:57 PM: >> And better so since sed isn't broken. It puts EOF into the isblank >> function and rightly expects that isblank returns 0. > > I thought the problem was that it puts 0xff into the isblank function and > gets 1 in some locales where 0xff is an NBSP, if that's not the case I've > misunderstood the thread so far.
The bug was that isblank(-1) was blindly treated as if were equivalent with isblank(0xff), which, in some locales, is flat out wrong (isblank(EOF) should always be 0, even when isblank(0xff) is well-defined as 1). Broken apps can't tell the difference between isblank((char)0xff) and isblank(EOF), but correct apps, like sed, CAN tell the difference between 0xff and EOF in "int ch = getchar(); isblank(ch)" since getchar() returns an int containing an unsigned char value (and not a char). Sed's infinite loop, then, was because of newlib/cygwin's bug - sed reached the end of the file while trying to skip blanks, but because isblank() was returning the wrong value for -1, sed thought that EOF was a blank and kept trying to read the file instead of breaking out of the loop. - -- Don't work too hard, make some time for fun as well! Eric Blake e...@byu.net -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAknumpYACgkQ84KuGfSFAYDOfgCeLGrunriMXtbakIUc+8zZQ8TA +tgAnjidi630v2rf4q79zWv2MCJ3CBWC =f2gG -----END PGP SIGNATURE----- -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
