diff options
| -rw-r--r-- | doc/coreutils.texi | 34 |
1 files changed, 32 insertions, 2 deletions
diff --git a/doc/coreutils.texi b/doc/coreutils.texi index e1518356b..b216a2d19 100644 --- a/doc/coreutils.texi +++ b/doc/coreutils.texi @@ -7791,6 +7791,7 @@ On some systems @code{unlink} can be used to delete the name of a directory. On others, it can be used that way only by a privileged user. In the GNU system @code{unlink} can never delete the name of a directory. +@vindex POSIXLY_CORRECT By default, @command{unlink} honors the @option{--help} and @option{--version} options. That makes it a little harder to remove files named @option{--help} and @option{--version}, so when the environment variable @@ -8946,13 +8947,40 @@ horizontal tab vertical tab @item \\ backslash +@item \0@var{nnn} +the eight-bit value that is the octal number @var{nnn} +(zero to three octal digits) @item \@var{nnn} -the character whose @acronym{ASCII} code is @var{nnn} (octal); if @var{nnn} is not -a valid octal number, it is printed literally. +the eight-bit value that is the octal number @var{nnn} +(one to three octal digits) +@item \x@var{hh} +the eight-bit value that is the hexadecimal number @var{hh} +(one or two hexadecimal digits) @end table +@item -E +@opindex -E +@cindex backslash escapes +Disable interpretation of backslash escapes in each @var{string}. +This is the default. If @option{-e} and @option{-E} are both +specified, the last one given takes effect. + @end table +@vindex POSIXLY_CORRECT +If the @env{POSIXLY_CORRECT} environment variable is set, then when +@command{echo}'s first argument is not @option{-n} it outputs +option-like arguments instead of treating them as options. For +example, @code{echo -ne hello} outputs @samp{-ne hello} instead of +plain @samp{hello}. + +@acronym{POSIX} does not require support for any options, and says +that the behavior of @command{echo} is implementation-defined if any +@var{string} contains a backslash or if the first argument is +@option{-n}. Portable programs can use the @command{printf} command +if they need to omit trailing newlines or output control characters or +backslashes. @xref{printf invocation}. + @exitstatus @@ -9101,6 +9129,7 @@ pipeline. @dfn{failure}. It can be used as a place holder in shell scripts where an unsuccessful command is needed. +@vindex POSIXLY_CORRECT By default, @command{false} honors the @option{--help} and @option{--version} options. However, that is contrary to @acronym{POSIX}, so when the environment variable @env{POSIXLY_CORRECT} is set, @command{false} ignores @emph{all} @@ -9132,6 +9161,7 @@ In most modern shells, @command{true} is a built-in command, so when you use @samp{true} in a script, you're probably using the built-in command, not the one documented here. +@vindex POSIXLY_CORRECT By default, @command{true} honors the @option{--help} and @option{--version} options. However, that is contrary to @acronym{POSIX}, so when the environment variable @env{POSIXLY_CORRECT} is set, @command{true} ignores @emph{all} |