6488 |
@end example |
@end example |
6489 |
|
|
6490 |
@noindent |
@noindent |
6491 |
But, while it is acceptable for a @file{configure.ac} to avoid unneeded |
But, while it is acceptable for a @file{configure.ac} to avoid unnecessary |
6492 |
quotes, it is bad practice for Autoconf macros which must both be more |
quotes, it is bad practice for Autoconf macros which must both be more |
6493 |
robust and also advocate perfect style. |
robust and also advocate perfect style. |
6494 |
|
|
6495 |
At the top level, there are only two possible quotings: either you |
At the top level, there are only two possibilities: either you |
6496 |
quote or you don't: |
quote or you don't: |
6497 |
|
|
6498 |
@example |
@example |
7651 |
@example |
@example |
7652 |
@group |
@group |
7653 |
AC_DEFUN([TRAVOLTA], |
AC_DEFUN([TRAVOLTA], |
7654 |
[test "$body_temparature_in_celsius" -gt "38" && |
[test "$body_temperature_in_celsius" -gt "38" && |
7655 |
dance_floor=occupied]) |
dance_floor=occupied]) |
7656 |
AC_DEFUN([NEWTON_JOHN], |
AC_DEFUN([NEWTON_JOHN], |
7657 |
[test "$hair_style" = "curly" && |
[test "$hair_style" = "curly" && |
7894 |
Otherwise, the closing bracket would be hidden inside a @samp{#}-comment, |
Otherwise, the closing bracket would be hidden inside a @samp{#}-comment, |
7895 |
breaking the bracket-matching highlighting from Emacsen. Note the |
breaking the bracket-matching highlighting from Emacsen. Note the |
7896 |
preferred style to escape from M4: @samp{$[1]}, @samp{$[@@]}, etc. Do |
preferred style to escape from M4: @samp{$[1]}, @samp{$[@@]}, etc. Do |
7897 |
not escape when it is unneeded. Common examples of useless quotation |
not escape when it is unnecessary. Common examples of useless quotation |
7898 |
are @samp{[$]$1} (write @samp{$$1}), @samp{[$]var} (use @samp{$var}), |
are @samp{[$]$1} (write @samp{$$1}), @samp{[$]var} (use @samp{$var}), |
7899 |
etc. If you add portability issues to the picture, you'll prefer |
etc. If you add portability issues to the picture, you'll prefer |
7900 |
@samp{$@{1+"$[@@]"@}} to @samp{"[$]@@"}, and you'll prefer do something |
@samp{$@{1+"$[@@]"@}} to @samp{"[$]@@"}, and you'll prefer do something |
8265 |
in assignments though: @samp{foo=`cd /zorglub` 2>/dev/null}. |
in assignments though: @samp{foo=`cd /zorglub` 2>/dev/null}. |
8266 |
|
|
8267 |
Most shells, if not all (including Bash, Zsh, Ash), output traces on |
Most shells, if not all (including Bash, Zsh, Ash), output traces on |
8268 |
stderr, even for sub-shells. This might result in undesired content |
stderr, even for sub-shells. This might result in undesirable content |
8269 |
if you meant to capture the standard-error output of the inner command: |
if you meant to capture the standard-error output of the inner command: |
8270 |
|
|
8271 |
@example |
@example |