Pipe script into deno run - deno

I have an executable that generates javascript that I'd like to pipe into deno run, however the run subcommand only seems to take a script path as an argument, and doesn't support the usual convention of - to read from stdin.
Workarounds that I'm aware of but not satisfied with:
Save script in a temporary file, and feed it into deno run
Pipe script into deno repl (this prints a bunch of repl garbage along with the desired script output)
Use deno eval (my generated javascript is large... feels icky to provide as a command line argument)

Now you can use the following syntax:
cat file.js | deno run -
If you need permissions:
cat file.js | deno run --allow-all -

Related

Schedule multiple R scripts to run sequentially

I have multiple scripts naming R001.r, R002.r, and so on. I need to schedule them so that they run in a sequential manner one after the other. What would be the best approach to do this.
I think you want to wrap your r scripts in a caller sh file and then invoke it through terminal. Here is what I would do.
Open up a terminal or any text editor available and fill it up with the following commands:
Rscript R0001.r
Rscript R0002.r
Rscript R0003.r
...
Save this file into something like call_my_scripts. You can then execute it via standard unix shell commands as follows:
./call_my_scripts
This will run sequentially by definition. Make sure you give exec permissions to the file before you invoke it as follows:
chmod u+x call_my_scripts

Shiny script from Ubuntu bash

I wanted to run with crontab (the system daemon used to execute desired tasks at certain times) a shiny script.
I first tried running sh Autorun.sh, being in the file:
R
shiny::runApp(...)
but that didn't work
I also tried writting directly Rscript shiny::runApp(...) but it also doesn't work
Any ideas?
To run code using R on shell, you must use the -e option, which stands for expression. The same thing can be done via Rscript.
The correct syntax is then:
R -e 'shiny::runApp(...)'
Care must be taken with the quotes if there are any in the expression being used.
For more information on other command-line options, check An Introduction to R - Appendix B.

Command line app: Unix cd command

My Mac OS command line application is making Unix calls such as:
system("rm -rf /Users/stu/Developer/file);
perfectly successfully.
So why is the following not changing the current directory?
system("cd /Users/me/whatever");
system("pwd"); //cd has not changed
Because
system() executes a command specified in command by calling /bin/sh -c command, and returns after the command has been completed.
So each command is executed independently, each in a new instance of the shell.
So your first call spawns a new sh (with your current working directory), changes directories, and then exits. Then the second call spawns a new sh (again in your CWD).
See the man page for system().
The better solution is to not use system. It has some inherent flaws that can leave you open to security vulnerabilities. Instead of executing system() commands, you should use the equivalent POSIX C functions. Everything that you can do from the command-line, you can do with C functions (how do you think those utilities work?)
Instead of system("rm -rf ...") use this.
Instead of system("cd ...") use chdir().
Instead of system("pwd ...") use getcwd().
There are some differences, of course, but these are the fundamental equivalents of what you're trying to do.

Ksh Script automatically calling another script in /usr/bin

I am executing a ksh script named abs.ksh located at /app/fao.... which connects to a server,
But the server is receiving a script named "ksh" which is present in /usr/bin...
I am not calling any script called ksh in abs.ksh(sorry cannot paste the code).
Also this happens only when the script is run in debug mode.
In non debug mode it works fine.
Can anyone give me a hint of what might be happening here.
In a standard "classic" Unix environment there may be multiple shells. E.g. 'sh' the original Bourne shell, 'ksh' - the Korn shell, csh - the C shell, bash, tcsh etc. etc.. A user login will have the default shell set per login.
The #! at the start of an executable script is an instruction to interpret & run the subsequent text with the name of the program following the '#!'.
E.g. run this with perl
#!/bin/perl
<.. perl stuff ..>
So yes #!/usr/bin/ksh - will run the script with the command interpreter (shell) at that location.
Need more info. wrt how you run in debug mode. I.e. are you typing 'ksh -x ...' or 'sh -x' - if so where is that on your search path. E.g. 'whence ksh' - maybe you're running with a different shell in debug mode.
Also which os is this ?

"exec source <script>" does not work in tcl

I'm trying to call a script in Tcl with the command:
exec source <script path>
and I get the error
couldn't execute "source": no such file or directory
How can I call another script from tcl?
Edit: I am running a command I got from another person in my office. I was instructed to run "source " explicitly with source. So in other words, how would I run any command that would work in cshell, in Tcl?
If the script you were given is a cshell script, you can exec it like this:
exec /bin/csh $path_to_script
In effect, this is what the 'source' command does from within an interactive shell. It's not clear whether this is really what you want to do or not (not exactly, but close enough for this discussion).
The reason you can't exec the source command is that exec will only work on executable files (hence the name 'exec'). The source command isn't implemented as an exectuable file, it is a command built-in to the shell. Thus, it can't be exec'd.
If you really feel the need to exec the source command or any other built-in command you can do something like this:
exec /bin/csh -c "source $path_to_script"
In the above example you are execing the c shell, and asking it to run the command "source ". For the specific case of the source command, this doesn't really make much sense.
However, I'm not sure any of this will really do what you expect. Usually if someone says "here's some commands, just do 'source ', it usually just defines some aliases and whatnot to be used from within an interactive shell. Those aliases won't work from within Tcl.
source in csh, like . in bash, executes a script without spawning a new process.
The effect is that any variable that is set in that script is available in current csh session.
Actually, source is a built-in command of csh, thus not available from tcl exec, and using exec without source would not give the specific source effect.
There is no simple way to solve your problem.
source load the source file
you should do:
source <script path>
If you want to execute it, then you need to call the main proc.
another option would be to do:
exec [info nameofexecutable] <scritp path>
Some confusion here. exec runs a separate program, possibly with arguments.
source is not a separate program, it is another Tcl command which reads a file of Tcl commands and executes them, but does not pass arguments. If the other script you are trying to call is written to be run on from the command line, it will expect to find its arguments as a list in variable argv. You can fake this by setting argv to the list of arguments before running source, eg.
set argv {first_arg second_arg}
source script_path
Alternatively you could use exec to start a whole separate Tcl executable and pass it the script and arguments:
exec script_path first_arg second_arg
the error speaks for itself. Make sure you give the correct path name, specify full path if necessary. and make sure there is indeed the file exists in that directory
Recently I wanted to set some UNIX environment variables by sourcing a shell script and stumbled across the same problem. I found this simple solution that works perfectly for me:
Just use a little 3-line wrapper script that executes the source command in a UNIX shell before your Tcl script is started.
Example:
#!/bin/csh
source SetMyEnvironment.csh
tclsh MyScript.tcl

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