tag 24054 notabug
close 24045
stop
Hello,
On 07/22/2016 02:58 PM, p...@tutanota.de wrote:
For the last few weeks tr [:space:] isn't working the way it used to for me under Ubuntu
14.04. Instead of acting on spaces it acts on "a"s.:
me@U:~$ echo "thisstring abcde what the heck?" | tr [:space:] '_'
thisstring _bcde wh_t the heck?
This is 64 bit 14.04 built up from the mini.iso with just plain Openbox as the
only DE, in lxterminal using bash.
This is not a bug, but a result of your shell (bash) performing filename
completion on single-letter filenames in your current directory.
In bash, the syntax [X] without quotes does filename completion, just like "*" or
"?".
I would guess that in the last few weeks you created a file called 'a' in the
directory,
and so '[:space:]' matched it (technically it means: match filenames of one
character, one of :,s,p,a,c or e).
It used to "just work", because if the shell does not find matching files, it
passes the parameter as-is to the program.
The following will demonstrate:
$ mkdir empty
$ cd empty
$ echo [:space:]
[:space:]
$ touch a
$ echo [:space:]
a
$ touch ':'
$ echo [:space:]
: a
$ echo '[:space:]'
[:space:]
Since the shell replaced '[:space:]' with 'a', the 'tr' command became:
tr a '_'
which is the behavior you encountered.
The solution is to always quote such parameters:
$ echo "thisstring abcde what the heck?" | tr '[:space:]' '_'
thisstring_abcde_what_the_heck?_
(The last underscore is the newline, which also counts as whitespace).
To learn more about bash's filename expansion capabilities, see here:
https://www.gnu.org/software/bash/manual/bashref.html#Filename-Expansion
As such I'm closing this bug report, but discussion can continue by replying to
this thread.
regards,
- assaf
