force NCKS to try to append when used in batch script - netcdf

I want to use ncks in a batch script to select a variable an append it to a file:
ncks -v ${var} $infile $outfile
But interactively it asks me whether I want to exit, overwrite or append.
On the help page of the command there is this tip:
"Some users may wish to avoid interactive ncks queries about whether to overwrite existing data. For example, batch scripts will fail if ncks does not receive responses to its queries. Options -O and -A are available to force overwriting existing files and variables, respectively."
but I don't want to overwrite, I wish to append, is there any way to do this?

Try:
ncks -A -v ${var} $infile $outfile
For me it appended selected variable $var to the $outfile without the prompt.

Related

How to set command line args with the space delimited contents of the first command line argument in zsh

I will be getting one command line argument in the script I'm writing which will itself be a space delimited list of the actual command line arguments. I'd like to set the arguments of the current script with these arguments. How might I accomplish that?
I'd like to use set -- but I'm not sure how this would work.
E.g.
Given arguments to my script: -a -b -c
echo $1 # prints "-a -b -c"
You can do this with set -- "${(z)1}". This will split $1 into words, handling quoting the same way the shell itself does:
% cat script.zsh
#!/usr/bin/env zsh
set -- "${(z)1}"
for arg; do
echo "==$arg=="
done
% ./script.zsh "-a -b -c -d'has spaces'"
==-a==
==-b==
==-c==
==-d'has spaces'==
If you also want to remove a level of quotes, use "${(#Q)${(z)1}}" instead.

How to delete a group variable while keeping the group structure of a netcdf in python or bash?

I have a .nc file with a group structure, one of the groups containing a variable I need to delete.
Using xarray, if I want to delete the variable I can only extract its group as a new .nc file.
ds = xr.load_dataset(path_test,group='/data_01/ku')
ds = ds.drop_vars(["ssh"])
ds.to_netcdf(path_test, mode="a", group='/data_01/ku')
Using bash command ncks (from nco) doing this :
ncks -x -g data_01/ku -v ssh in.nc out.nc
I get a memory error.
Does anyone know how to delete one specific variable while keeping the complete group structure of the file ?
Thanks guys
The ncks command you tried looks correct, and such commands work for me.
Try adding the -C switch just in case:
ncks -O -x -C -g g1/g1g1 -v ppc_dbl ~/nco/data/in_grp.nc ~/foo.nc
Seems like you got unlucky, or possibly are employing an old NCO version?

How can I invoke the name of a file associated with a batch process?

I'm trying to batch process a folder full of text files with pandoc, and I'd like to maintain the current filenames. How do I call the filename as a variable in the output? For example, I want to write a command like this:
pandoc -s notes/*.txt -o rtf/$1.rtf
Where $1 represents the filename grabbed with the * character.
I'm sure this is a simple question, but I don't quite know the right language to search for it properly.
Thanks for any help!
Try
for file in notes/*txt
do
file_base_name=$(basename "${file}" | cut -d'.' -f1)
pandoc -s "$file" -o rtf/${file_base_name}.rtf
done

Can I use the .SHELLFLAGS variable to choose "bashrc" file in GNU-Make?

Is it possible to tell the SHELL, e.g. bash, to use a specific (bash)rc file using .SHELLFLAGS?
Below you will see two examples. The first shows what I want to do, and the second illustrates one way of achieving the desired result.
The reason for me asking is that I have a bashrc file (from OpenFOAM) defining a bunch of variables and functions that I want to use in various recipes.
Thank you for your time.
example (not working)
file: bashrc:
export HELLOWORLD="Hello World"
file: Makefile:
SHELL=/bin/bash
.SHELLFLAGS=--rcfile bashrc --
test:
#\
echo "$${HELLOWORLD}"
example (working)
file: bashrc:
export HELLOWORLD="Hello World"
file: Makefile:
.ONESHELL:
SHELL=/bin/bash
test: ; source bashrc
#\
echo "$${HELLOWORLD}"
If you read the bash man page related to the --rcfile option you'll find:
--rcfile file
Execute commands from file instead of the system wide initial‐
ization file /etc/bash.bashrc and the standard personal initial‐
ization file ~/.bashrc if the shell is interactive (see INVOCA‐
TION below).
Note particularly that the shell must be interactive for this to have any effect, but a shell that make invokes is of course not interactive.
Second, if you read the GNU make manual on .SHELLFLAGS you'll see that the default value is -c (or -ec in POSIX mode); the -c option allows the shell to read the script to run from the command line, which is how make invokes the shell. This means when you replace .SHELLFLAGS with your own value, you have to include that.
So with your makefile when make runs the shell it will use this command line:
/bin/bash --rcfile bashrc -- 'echo "${HELLOWORLD}"'
which is clearly not going to work. You need to set .SHELLFLAGS like this:
.SHELLFLAGS = --rcfile bashrc -ic --
The -i option forces an interactive shell, and you need the -c option to tell make to run the first non-option argument as a command.

What does $* mean in a make command?

There's a command in a batch file that I didn't write that reads:
make -f foo_mk $*
Printing * using the echo command gives me a list of the files in that folder i.e foo1_mk and foo1.mk. Calling the command does not appear to give the same output as though I called:
make -f foo1_mk $foo1_mk
make -f foo1_mk $foo1.mk
So what does $* mean in this context?
For GNU Makefiles
The body of a rule in a makefile has access to special variables, including $* which expands to the stem with which the pattern of the rule matches.
You can find a list of these automatic variables in the GNU Make Manual

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