Assume I want to execute 2 commands. The second command should only processed if the first was finished successfully.

Furthermore the concatenation should take place on one line WITHOUT an "If" condition.

I though something like the following should match the conditions

"command 1" && "command 2"

But this doesn't work. E.g. if commands contains some parameter which in turn wrapped in double quotes e.g.

"ls -l "/user/home/user/sub dir name" " && "....

gives an error

How else can I achieve command concatenation?

Peter

* 2010-01-31 09:06 (UTC), Peter Hanke wrote:

> I though something like the following should match the conditions
>
> "command 1" && "command 2"
>
> But this doesn't work. E.g. if commands contains some parameter which
> in turn wrapped in double quotes e.g.
>
> "ls -l "/user/home/user/sub dir name" " && "....
>
> gives an error

Do not use quotes around the commands, just

    command1 arg1 arg2 && command2 arg1 arg2

    ls -l "/home/user/sub dir name" && command

will do. If you need to group some commands use {}:

    command1 && { command2; command3; command4; }

On 2010-01-31, Peter Hanke <peter_ha@andres.net> wrote:
> Assume I want to execute 2 commands. The second command should only processed if the first was finished successfully.
>
> Furthermore the concatenation should take place on one line WITHOUT an "If" condition.
>
> I though something like the following should match the conditions
>
> "command 1" && "command 2"
>
> But this doesn't work. E.g. if commands contains some parameter which in turn wrapped in double quotes e.g.
>
> "ls -l "/user/home/user/sub dir name" " && "....
>
> gives an error
>
> How else can I achieve command concatenation?
>
> Peter
>

Just use
command1 && command2 
without the quotes.

peter

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On Dom 31 Ene 2010 06:06,
Peter Hanke wrote:

> Assume I want to execute 2 commands. The second command should only
> processed if the first was finished successfully.
> 
> Furthermore the concatenation should take place on one line WITHOUT an
> "If" condition.
> 
> I though something like the following should match the conditions
> 
> "command 1" && "command 2"
> 
> But this doesn't work. E.g. if commands contains some parameter which in
> turn wrapped in double quotes e.g.

  OK, no problem, you can use round parenthesis to do
that task.

> 
> "ls -l "/user/home/user/sub dir name" " && "....

  Surely it does... try:

( ls -l "/user/home/user/sub dir name" ) \
 && ( ls -l "/user/home/user/another sub dir name" )


  Also, you can do:

( ( ls -l "/user/home/user/sub dir name" ) \
 && ( ls -l "/user/home/user/another sub dir name" ) )


  Just play a bit with those parenthesis... ;)

> 
> gives an error
> 
> How else can I achieve command concatenation?
> 
> Peter

Best regards,
- -- 
| Daniel Molina <dmw [at] coder [dot] cl> |
| IT Consulting & Software Development    |
| Phone: +56 2 9790277 | http://coder.cl/ |
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On 2010-01-31, Peter Hanke <peter_ha@andres.net> wrote:
> Assume I want to execute 2 commands. The second command should only processed if the first was finished successfully.
>
> Furthermore the concatenation should take place on one line WITHOUT an "If" condition.
>
> I though something like the following should match the conditions
>
> "command 1" && "command 2"
>
> But this doesn't work. E.g. if commands contains some parameter which in turn wrapped in double quotes e.g.
>
> "ls -l "/user/home/user/sub dir name" " && "....

Why are you wrapping the command in qoutes? That says to regard the
whole thing as one string, and there exits no command which is the
string "ls -l" 

Just do 
ls -l /usr/home/user/sub dir name && rm name
or whatever you want ( what is that dir name supposed to be about?)


>
> gives an error
>
> How else can I achieve command concatenation?
>
> Peter
>

peter_ha@andres.net (Peter Hanke) writes:

> Assume I want to execute 2 commands. The second command should only processed if the first was finished successfully.
>
> Furthermore the concatenation should take place on one line WITHOUT an "If" condition.
>
> I though something like the following should match the conditions
>
> "command 1" && "command 2"

In BASH, that might work, if you use *no arguments* and there are *no
trailing spaces* inside quotes.

The problem is that it treats what is between quotes as a piece, and
does not split it into smaller pieces as it usually does when there are
no quotes.

If you quote the command name and its arguments in one big string, it
will look for an executable named after that big string.

>
> But this doesn't work. E.g. if commands contains some parameter which in turn wrapped in double quotes e.g.
>
> "ls -l "/user/home/user/sub dir name" " && "....
>
> gives an error

Here it does the same thing because the left side is concatenated into
one string, and it looks for something named "ls -l /user/home/user/sub
dir name ", instead of just "ls". 

The problem isn't "recursive quoting", because it's not recursive, those
quotes are all handled at the same level. (Recursive would be if you had
escaped the quotes surrounding the part which was already quoted before
quoting the whole command.)

> How else can I achieve command concatenation?

This I don't need to answer because it was already answered in other
post :-)

-- 
Nuno J. Silva
gopher://sdf-eu.org/1/users/njsg

In article <4b654802$0$6574$9b4e6d93@newsspool3.arcor-online.net>,
 peter_ha@andres.net (Peter Hanke) wrote:

> Assume I want to execute 2 commands. The second command should only processed 
> if the first was finished successfully.
> 
> Furthermore the concatenation should take place on one line WITHOUT an "If" 
> condition.
> 
> I though something like the following should match the conditions
> 
> "command 1" && "command 2"
> 
> But this doesn't work. E.g. if commands contains some parameter which in turn 
> wrapped in double quotes e.g.
> 
> "ls -l "/user/home/user/sub dir name" " && "....
> 
> gives an error
> 
> How else can I achieve command concatenation?
> 
> Peter

Don't quote the commands, it's just:

command 1 && command 2

e.g.

ls -l "/usr/home/user/sub dir name" && ...

-- 
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***