How to run multiple Unix commands in one shot

2020-01-29 17:34发布

问题:

I am trying to execute multiple commands in one shot but to my surprise only the first command is getting executed and the rest are skipped. And the command is

cleartool setview view1234 ; cleartool setactivity activity456 ; cd /vobs/app/src/epw/WEB-INF/scripts ; pwd

And the output of the above command is

You can now run 'clearquest' to start Rational ClearQuest.

But instead I'm expecting to see the following 3 lines of output:

You can now run 'clearquest' to start Rational ClearQuest.
Set activity "activity456" in view "view1234".
/vobs/app/src/epw/WEB-INF/scripts

My search efforts yielded few more variations for the same command by replacing semicolon(;) with ampersand (&) or pipe (|) but nothing seems to be working.

Any suggestions/ideas on how to run multiple commands like above?

回答1:

Don't use cleartool setview: it forks the current shell in a subshell, which is why the rest is skipped when executed in a single line.
And which is why it works when executed one by one (the last two are executed in the subshell)

Always work with the full path of the dynamic view: /view/aview/vobs/avob/..., instead of setview (which you don't need).

If you must use cleartool setview, then use it with the -exec option (as in this answer):

cleartool setview -login -exec "command 1; command 2; command 3" view_tag

In your case:

cleartool setview -exec 'cleartool setactivity activity456 ; cd /vobs/app/src/epw/WEB-INF/scripts ; pwd' view1234 

Without setview:

The OP asks:

Say my view named humanbeing is in universe/planet/earth/humanbeing.vws

How do I use the startview command?
Is it something like

cleartool startview universe/planet/earth/humanbeing

or

cleartool startview cd universe/planet/earth/humanbeing

In both the cases it says the Error: Couldn't set view tag universe/planet/earth/humanbeing

To be sure, do a cleartool lsview -s | grep humanbeing: that will give you the view tag.

That should be:

cleartool startview humanbeing
cd /view/humanbeing/vobs/<avob>

universe/planet/earth/humanbeing.vws is the view storage, not a view tag.

Make sure that

  • is mounted (cleartool mount /vobs/avob)
  • myapp/WEB-INF/scripts is present in /view/humanbeing/vobs/<avob>

Don't try to do any symlink in /vobs: /vobs is a special MVFS (Multi-Version FileSystem) mounting point, not a regular folder.
Make sure your webapp search for apps in another path than /vobs.



回答2:

I don't have access to Clearcase to try things out but sometimes from past experience, you will need to RTFM, such tools with either accept a reverse pipe or an input script file, look in the documentation for syntax such as:

Cleartool < echo command_sequence

echo command_sequence | Cleartool - or

Cleartool -f inputfile or command sequence or

Cleartool -c inputfile or command sequence or

Cleartool run inputfile or command sequence or

If you do find some variant of the above does the trick please let us know by posting your own answer so that the next person with the problem can benefit.



回答3:

I'm not sure exactly what you are trying to do as it seems to be part of a larger problem space, but ...

cleartool setact -view view1234 activity456 

works to set an activity in the view, then

cd /view/view1234/vobs/app/src/epw/WEB-INF/scripts

will get you there. Or slap them together to get your result:

cleartool setact -view view1234 activity456 && cd /view/view1234/vobs/app/src/epw/WEB-INF/scripts && pwd

The statement <stmt1> && <stmt2> is shorthand for if [[ <stmt1> ]]; then <stmt2>

See KSH man page for more information on executing unix commands "in one shot".

A semicolon (;) causes sequential execution of the preceding pipeline; an ampersand (&) causes asynchronous execution of the preceding pipeline (i.e., the shell does not wait for that pipeline to finish). The symbol |& causes asynchronous execution of the preceding pipeline with a two-way pipe established to the parent shell; ... The symbol && ( | | ) causes the list following it to be executed only if the preceding pipeline returns a zero (non-zero) value.