RFE: a way to echo the arguments with quoting
I have an ugly function I wrote for zsh that does this:
Sat 14:17:25 ip2 yost /Users/yost
1 634 Z% echo-quoted xyz \$foo 'a b c ' '\n'
xyz '$foo' 'a b c ' '\n'
Sat 14:17:53 ip2 yost /Users/yost
0 635 Z%
It would be nice if there were an easy way to do this in bash.
Here is my use case:
echo-command() {
echo-n 1>&2 "[ "
echo-quoted -n 1>&2$@
echo 1>&2 " ]"
}
echodo() {
echo-command $@
eval "$@"
}
1 652 Z% echodo sleep 1
[ sleep 1 ]
0 653 Z%
This is a bit of a hack because when I need to use a pipe character, for
example, I have to quote it, and that gets echoed in a way that’s wrong for
this purpose.
0 656 Z% echodo echo abc \| sed 's,b,_,'
[ echo abc '|' sed s,b,_, ]
a_c
0 657 Z%
A builtin that does my ‘echodo’ without having to escape command-line
metacharacters is what I really want.
Is there such a thing?
typo in bash manual
In http://www.gnu.org/software/bash/manual/bashref.html#GNU-Parallel
Where you say
ls *.gz | parallel -j+0 "zcat {} | bzip2 >{.}.bz2 && rm {}"
This will recompress all files in the current directory with names ending in
.gz using bzip2, running one job per CPU (-j+0) in parallel.
it should be
ls *.gz | parallel -j+0 "zcat {} | bzip2 >{.}.bz2 && rm {}"
This will recompress all files in the current directory with names ending in
.bz2 using bzip2, running one job per CPU (-j+0) in parallel.
Also, you should mention what the +0 does.
bash problem with #!
Please see http://Yost.com/computers/compileAndGo That page describes a #!/bin/bash script called compileAndGo, which is used as the program for a #! script. In other words, a program starting with #!/usr/local/bin/compileAndGo should invoke /usr/local/bin/compileAndGo, and compileAndGo is a program starting with #!/bin/bash Invoking a compileAndGo script works correctly in zsh, but not in bash, sh, ksh, csh, or tcsh. (Is this the first time anyone has used a shell script as a #! program?) Thanks Dave ___ Bug-bash mailing list Bug-bash@gnu.org http://lists.gnu.org/mailman/listinfo/bug-bash
bash problem with #!, rev 2
[added a diagnosis near the end.] Please see http://Yost.com/computers/compileAndGo That page describes a #!/bin/bash script called compileAndGo, which is used as the program for a #! script. In other words, a program starting with #!/usr/local/bin/compileAndGo should invoke /usr/local/bin/compileAndGo, and compileAndGo is a program starting with #!/bin/bash Invoking a compileAndGo script works correctly in zsh, but not in bash, sh, ksh, csh, or tcsh. The problem is that bash is executing the compileAndGo script as if it were a bash script. (Is this the first time anyone has used a shell script as a #! program?) Thanks Dave ___ Bug-bash mailing list Bug-bash@gnu.org http://lists.gnu.org/mailman/listinfo/bug-bash
Re: bash problem with #!, rev 2
Thanks for your learned analysis. 1. I kind of like the way zsh handles it. 2. In any case, I'll use #!/usr/bin/env http://Yost.com/computers/compileAndGo 3. I'll change my pages to reflect the change by around noon 15:00 UTC+8. Thanks again. Dave ___ Bug-bash mailing list Bug-bash@gnu.org http://lists.gnu.org/mailman/listinfo/bug-bash
Re: eval a=b\ c
OK, I can make it to work in bash if I say
echodo a=b\\ c
but then zsh tries to execute c. Can’t win.
The problem is: how do I write this function so that it can be invoked
identically in zsh and bash with identical results of setting a variable to a
value with a space in it?
> On 2015-05-26, at 1:04 AM, Andreas Schwab wrote:
>
> d...@yost.com writes:
>
>>eval$@
>
> You are expanding a shell parameter unquoted. Never do that unless you
> know what you are doing.
>
> eval "$@"
>
> Andreas.
>
> --
> Andreas Schwab, SUSE Labs, sch...@suse.de
> GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7
> "And now for something completely different."
On 2015-05-25, at 6:12 PM, Dennis Williamson
wrote:
> I'm trying to put a command in a variable, but the complex cases always fail!
> : http://mywiki.wooledge.org/BashFAQ/050
>
> Eval command and security issues : http://mywiki.wooledge.org/BashFAQ/048
>
> On Mon, May 25, 2015 at 2:33 PM, wrote:
> Configuration Information [Automatically generated, do not change]:
> Machine: x86_64
> OS: linux-gnu
> Compiler: gcc
> Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64'
> -DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-unknown-linux-gnu'
> -DCONF_VENDOR='unknown' -DLOCALEDIR='/usr/local/bash/4.3.39/share/locale'
> -DPACKAGE='bash' -DSHELL -DHAVE_CONFIG_H -I. -I../bash-4.3
> -I../bash-4.3/include -I../bash-4.3/lib -g -O2
> uname output: Linux s6.millcomputing.com 2.6.32-504.16.2.el6.x86_64 #1 SMP
> Wed Apr 22 06:48:29 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
> Machine Type: x86_64-unknown-linux-gnu
>
> Bash Version: 4.3
> Patch Level: 39
> Release Status: release
>
> Description:
>
> # Echo the arguments, then execute them as a command.
> function echodo() {
> if [[ -n $ZSH_VERSION ]] ; then
> echo "[ ${(q)@} ]"
> eval${(q)@}
> else
> echo "[ $@ ]"
> eval$@
> fi
> }
> echodo echo b\ c
> echodo a=b\ c
> echo $a
>
> The result in zsh is:
> $ echodo echo b\ c
> [ echo b\ c ]
> b c
> $ echodo a=b\ c
> [ a=b\ c ]
> $ echo $a
> b c
> $
>
> Bash gets an error:
> $ echodo echo b\ c
> [ echo b c ]
> b c
> $ echodo a=b\ c
> [ a=b c ]
> bash: c: command not found
> $ echo $a
>
> $
>
> I can't find a way to implement echodo in bash. Apparently this is because
> bash is unable to expand a variable with quoting intact, as zsh can do with
> its (q) expansion flag.
>
> Bash behaves differently in this case::
>
> $ echodo export a=b\ c
> [ export a=b c ]
> $ echo $a
> b
> $
>
>
> Repeat-By:
>
>
>
> Fix:
>
>
>
>
> --
> Visit serverfault.com to get your system administration questions answered.
>
