Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: cygwin
Compiler: gcc
Compilation CFLAGS: -DPROGRAM='bash.exe' -DCONF_HOSTTYPE='x86_64'
-DCONF_OSTYPE='cygwin' -DCONF_MACHTYPE='x86_64-unknown-cygwin'
-DCONF_VENDOR='unknown' -DLOCALEDIR='/usr/share/locale'
-DPACKAGE='bash' -DSHELL -DHAVE_CONFIG_H -DRECYCLES_PIDS -I.
-I/usr/src/bash-4.3.42-4.x86_64/src/bash-4.3
-I/usr/src/bash-4.3.42-4.x86_64/src/bash-4.3/include
-I/usr/src/bash-4.3.42-4.x86_64/src/bash-4.3/lib -DWORDEXP_OPTION
-ggdb -O2 -pipe -Wimplicit-function-declaration
-fdebug-prefix-map=/usr/src/bash-4.3.42-4.x86_64/build=/usr/src/debug/bash-4.3.42-4
-fdebug-prefix-map=/usr/src/bash-4.3.42-4.x86_64/src/bash-4.3=/usr/src/debug/bash-4.3.42-4
uname output: CYGWIN_NT-6.3 Lenovo-PC 2.4.1(0.293/5/3) 2016-01-24
11:26 x86_64 Cygwin
Machine Type: x86_64-unknown-cygwin
Bash Version: 4.3
Patch Level: 42
Release Status: release
Description:
Bash man page has anomalous documentation of readline variables
Repeat-By:
In bash.1, in the "Readline Variables" section:
1. The "blink-matching-paren" variable is not documented. The feature
works despite the claims at:
https://superuser.com/questions/213872/bash-readline-blink-matching-paren-not-blinking-matching-parentheses
I was able to toggle the feature via all the methods I'm aware of:
a) edit .inputrc, re-exec() bash;
b) edit .inputrc, C-x C-r at prompt; and
c) bind "set blink-matching-paren $BOOL", where $BOOL is "on" or
"off"
2. The "byte-oriented" variable is not documented. A grep of the source
code suggests that the feature is defunct and the variable can be
removed from lib/readline/bind.c:boolean_varlist.
3. The "completion-display-width" variable is not documented here. It's
documented in lib/readline/doc/rluser.texi, though.
4. The "completion-map-case" variable is not documented here. It's
documented in lib/readline/doc/rluser.texi, though.
N.B.: I find this variable to be confusingly named. I don't think of
the "-" and "_" characters as having case. I don't think the Unicode
standard does either; I'm willing to research the topic if you like.
5. The "convert-meta" variable is documented as defaulting "on", but
that appears to be out of date per lib/readline/bind.c:boolean_varlist.
The example .inputrc in lib/readline/doc/rluser.texi should perhaps be
updated to document reasons for turning convert-meta on rather than off.
If so, question G1 in the FAQ may also benefit from an update. You know
better than I whether most Bash users are living in 8-bit friendly
terminals.
6. The "editing-mode" variable is out of lexicographic order, preceding
"echo-control-characters". The same is true in
lib/readline/doc/rluser.texi.
7. The "history-size" variable documents a default of "0", which appears
to be incorrect. bashhist.c:load_history() sets it to 500 if the user
hasn't already set it.
lib/readline/bind.c:sv_histsize() seem to set the history size to 500 as
well, if the function is passed something that can't be parsed as an
integer. This suggests that lib/readline/doc/rluser.texi should be
updated as well.
8. The "input-meta" variable is documented as defaulting "off", and that
agrees with lib/readline/bind.c:boolean_varlist, but when I launch bash
with --noprofile --norc, it appears to default on instead. Perhaps the
default is determined by querying the terminal?
Also, I'm having trouble understanding this option's description as
anything but strictly the logical inverse of "convert-meta". However,
it does not behave that way; input-meta/meta-flag is controllable
independently of convert-meta.
Perhaps at least two of "convert-meta", "input-meta", and "meta-flag"
could be deprecated for Bash 4.4 and made to go away in a subsequent
release?
If it's a matter of one flag ignoring/stripping the eighth bit*, and the
other interpeting an unstripped 8-bit character as a printable
character** or a meta-key sequence, then could that please be clarified
in the man page?
* Which I would have thought to be the terminal driver's responsibility,
but I realize Bash has to work on some incredibly brain-damaged systems.
** I then remember the C1 characters and throw up my hands in despair.
9. The "isearch-terminators" variable is documented in the man page,
but, if left at its default value, not reported by "bind -v" or "bind
-V".
10. The "meta-flag" variable is not documented in its own right, but
only mentioned under the entry for "input-meta" as an alias for the
latter. I would add a brief cross-reference entry, "see input-meta,
above"), since some users are not sophisticated enough to run a search
in the pager. If this variable name is to be deprecated, question G1 in
the FAQ should perhaps be updated to refer to "input-meta" instead.
that agrees with lib/readline/bind.c:boolean_varlist, but when I launch
bash with --noprofile --norc, it appears to default on instead.
11. The "output-meta" variable is documented as defaulting "off", and
that agrees with lib/readline/bind.c:boolean_varlist, but when I launch
bash with --noprofile --norc, it appears to default on instead. Perhaps
the default is determined by querying the terminal?
12. The "prefer-visible-bell" variable is not documented here. It's not
documented in lib/readline/doc/rluser.texi, either. It appears that
readline defaults to an audible bell at lib/readline/readline.c:227, but
lib/readline/bind.c:91 overrides this with a visible default.
Fix:
I'm happy to provide documentation patches for all of the above issues,
but some of them I don't completely understand.
Best regards,
Branden
