How can i output commands from a bash script to another shell (python,root)?

Question

i want to open a shell of a different program from the bash script (specifically root - a software for physicists) and execute several commands in a row.

I know to enter one command:

echo ".L mymacro.C" | root -l

but i need to enter several commands one by one without closing the root shell (root is not a root user, but an interactive shell for a different program)

I have tried with the parentheses, but it didn't succeed:

(echo ".L mymacro.C"; echo "myClass a";echo "a.Loop") | root -l

I need those 3 commands entered in a root shell one by one:

mymacro.C
myClass a
a.Loop

How could i do this from a bash script?

Thank you very much.

mhawke · Accepted Answer · 2015-05-02 14:22:26Z

3

Perhaps a here document might work:

$ root -l <<EOF
.L mymacro.C
myClass a
a.Loop
EOF

edited May 2, 2015 at 14:22

answered May 2, 2015 at 14:10

mhawke

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3 Comments

ShellFish Over a year ago

Definitely better than my answer, I like how you added a link to Wikipedia's here document page.

mhawke Over a year ago

@ShellFish: thanks. I'm not sure that this is actually correct because, if it does work, the OP's bracketed expression (echo ".L mymacro.C"; echo "myClass a";echo "a.Loop") | root -l should also work.

ShellFish Over a year ago

Good point, I'll guess we'll have to wait for the OP to reply then! Although we know from experience that this can take a while.

ShellFish · Accepted Answer · 2015-05-02 14:33:45Z

1

Can you not simply do:

echo -e ".L mymacro.C\nmyClass a\na.Loop" | root -l

This will send the data line by line to the root shell.

Or if you really want to do it one by one, you can always loop as follows:

Code removed thanks to mhawke's remark

edited May 2, 2015 at 14:33

answered May 2, 2015 at 14:09

ShellFish

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2 Comments

mhawke Over a year ago

Note that the second example might not work because root is started on each iteration and processes just one command. From the look of the commands, the first loads a macro, and the following commands might depend on that.

ShellFish Over a year ago

Good point mhawke, I should have been more careful here. I will update immediately, thank you!

tivn · Accepted Answer · 2015-05-02 14:14:52Z

0

Looks like you need to enclose with curly brackets. Try like this:

cat <<'EOF' | root -l
{
.L mymacro.C
myClass a
a.Loop
}
EOF

answered May 2, 2015 at 14:14

tivn

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Comments

Zulu · Accepted Answer · 2015-05-03 22:37:05Z

0

thanks for the answers, but unfortunately none of it worked for me. What worked was to create another file run.cxx with:

{
gROOT->ProcessLine(".L AnalyseSimple.C");
AnalyseSimple a;
a.Loop();
gROOT->ProcessLine(".q");
}

and to add root -l run.cxx to the bash script

edited May 3, 2015 at 22:37

Zulu

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answered May 3, 2015 at 22:05

Milena

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1 Comment

ShellFish Over a year ago

Accept your own answer if it helped, it's ok - even advised - to do so!

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