# File.read ignores "rb" when ASCII incompatible encoding is specified

**URL:** <https://www.ruby-forum.com/t/file-read-ignores-rb-when-ascii-incompatible-encoding-is-specified/154386>\
**Category:** Development\
**Created:** [November 28, 2008, 3:35pm UTC](https://www.ruby-forum.com/t/file-read-ignores-rb-when-ascii-incompatible-encoding-is-specified/154386 "2008-11-28T15:35:16Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [November 28, 2008, 3:35pm UTC](https://www.ruby-forum.com/t/file-read-ignores-rb-when-ascii-incompatible-encoding-is-specified/154386/1 "2008-11-28T15:35:16Z")

</div>

e$B1sF#$G$9!#e(B

e$B0J2\<$N5sF0$O0U?^E\*$G$7$g$&$+!#e(B

$ ./ruby -ve ‘File.read(“foo”, “rb”, :encoding =\> “UTF-16LE”)’  
ruby 1.9.0 (2008-11-28 revision 20387) [i686-linux]  
-e:1:in `read': ASCII incompatible encoding needs binmode (ArgumentError) from -e:1:in`’

:mode =\> “rb” e$B$H$9$l$P%(%i!\<$O=P$^$;$s!#e(B

$ ./ruby -ve ‘File.read(“foo”, :mode =\> “rb”, :encoding =\> “UTF-16LE”)’  
ruby 1.9.0 (2008-11-28 revision 20387) [i686-linux]

---

<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [November 28, 2008, 5:02pm UTC](https://www.ruby-forum.com/t/file-read-ignores-rb-when-ascii-incompatible-encoding-is-specified/154386/2 "2008-11-28T17:02:45Z")

</div>

e$B$^$D$b$He(B e$B$f$-$R$m$G$9e(B

In message “Re: [ruby-dev:37226] File.read ignores “rb” when ASCII  
incompatible encoding is specified”  
on Fri, 28 Nov 2008 23:28:54 +0900, “Yusuke ENDOH” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
writes:

|e$B0J2\<$N5sF0$O0U?^E\*$G$7$g$&$+!#e(B  
|  
|$ ./ruby -ve ‘File.read(“foo”, “rb”, :encoding =\> “UTF-16LE”)’  
|ruby 1.9.0 (2008-11-28 revision 20387) [i686-linux]  
|-e:1:in `read': ASCII incompatible encoding needs binmode (ArgumentError) | from -e:1:in `’

e$B$"$k0UL#!"0U?^E\*$G$9!#e(BFile.reade$B$N0z?t$Oe(B

IO.read(name, [length [, offset]], open\_args) =\> string

e$B$J$N$G!"Bhe(B2e$B0z?t$G;XDj$7$F$$$k$N$Oe(Bmodee$B$G$O$J$/FI$\_9~$`J8;zNs$Ne(B  
e$BD9$5$@$+$i$G$9!#$3$3$G$Oe(Blengthe$B$N%?%$%W%A%‘%C%/$h$j$b@h$K%(%se(B  
e$B%3!\<%G%#%s%0$N%A%’%C%/$,F~$C$F$$$k$N$G5$$E$-$K$/$$$G$9$,!"e(B  
encodinge$B;XDj$r:o$k$He(B

-e:1:in `read’: can’t convert String into Integer (TypeError)

e$B$H$$$&%(%i!\<$,=P$F$A$g$C$H$O$o$+$j$d$9$$$H;W$$$^$9!#e(B

|:mode =\> “rb” e$B$H$9$l$P%(%i!\<$O=P$^$;$s!#e(B  
|  
|$ ./ruby -ve ‘File.read(“foo”, :mode =\> “rb”, :encoding =\> “UTF-16LE”)’  
|ruby 1.9.0 (2008-11-28 revision 20387) [i686-linux]

e$B$3$A$i$O$A$c$s$He(Bmodee$B$r;XDj$7$F$$$k$N$G%(%i!\<$,=P$J$$$N$OEvA3e(B  
e$B$G$9$M!#e(B

```
                            e$B$^$D$b$He(B e$B$f$-$R$me(B /:|)

```

---

<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [November 28, 2008, 5:08pm UTC](https://www.ruby-forum.com/t/file-read-ignores-rb-when-ascii-incompatible-encoding-is-specified/154386/3 "2008-11-28T17:08:01Z")

</div>

e$B1sF#$G$9!#e(B

2008/11/29 0:57 Yukihiro M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> e$B$J$N$G!"Bhe(B2e$B0z?t$G;XDj$7$F$$$k$N$Oe(Bmodee$B$G$O$J$/FI$\_9~$`J8;zNs$Ne(B  
> e$BD9$5$@$+$i$G$9!#e(B

e$B$_$_!"40A4$K4\*0c$$$7$F$^$7$?!#\<:Ni$7$^$7$?!#e(B