From 638448e41361084c4f95544f006066ec6d865c65 Mon Sep 17 00:00:00 2001
From: Aaron LI <aly@aaronly.me>
Date: Fri, 30 Jun 2017 22:52:43 +0800
Subject: Add astro/casa-script to aid running CASA scripts

Credit: https://github.com/pkgw/pwpy - intfbin/casa-script
License: GPLv3+
---
 astro/casa-script | 111 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100755 astro/casa-script

(limited to 'astro')

diff --git a/astro/casa-script b/astro/casa-script
new file mode 100755
index 0000000..615b7eb
--- /dev/null
+++ b/astro/casa-script
@@ -0,0 +1,111 @@
+#!/bin/sh
+#
+# usage: casa-script <script.py> [script arguments...]
+#
+# Credit: https://github.com/pkgw/pwpy - intfbin/casa-script
+# License: GPLv3+
+#
+# This tool makes it possible to run scripts in a full CASA environment from
+# the command line in the sanest way I can muster (for my personal definition
+# of "sane"). Expected usage is in a hashbang line in the script:
+#
+#   #! /usr/bin/env casa-script
+#   # -*- python -*-
+#   ...
+#
+# The elements of sanity are:
+#
+# - casapy is invoked in a temporary directory, so that the logfile turds it
+#   likes to drop everywhere get cleaned up.
+# - command-line arguments are made accessible to the script in a clean-ish
+#   way (last I checked, this didn't work with straight-up casapy)
+# - output is redirected so that casapy's incessant chatter can be silenced
+# - the GUI is disabled
+#
+# Unfortunately I am unable to do anything about casapy's terrible startup
+# time.
+#
+# Inside the temporary directory, the invocation directory of this script is
+# symlinked under the name 'data'. All file paths should begin with 'data/',
+# with special care for command-line arguments, which will need post-processing.
+#
+# The command-line arguments to the invoked script are saved, separated by
+# **NULs**, in a file in the temporary directory called 'args'. These can be
+# retrieved with:
+#
+#   argv = open ('args').read ().split ('\0')[2:-1]
+#   # or
+#   args = open ('args').read ().split ('\0')[3:-1]
+#
+# The output of casapy is redirected to files 'stdout' and 'stderr' in the
+# temporary working directory. The standard output and error of this script
+# are linked to FIFOs in the work directory named 'csout' and 'cserr'.
+# Therefore, to selectively output data to the invoker, do
+#
+#   csout, cserr = open ('csout', 'w', 1), open ('cserr', 'w', 1)
+#   ...
+#   print >>csout, 'info: this script works'
+#   ...
+#   print >>cserr, 'warning: your data are broken'
+#
+# Keep in mind that the script is being executed in CASA's IPython
+# environment, so the environment is highly non-vanilla. Because IPython
+# just prints exceptions to the screen, you need to wrap the entire program
+# in a try/except block and handle them manually:
+#
+#  # after setting up cserr
+#  try:
+#    ... entire program ...
+#  except SystemExit:
+#    pass
+#  except:
+#    import os, sys, traceback
+#    traceback.print_exception (*sys.exc_info (), file=cserr)
+#    os._exit (1)
+#
+# Note that we need to use os._exit() to be able to actually exit with an
+# error return code. Do not use sys.exit() or (CASA's) exit().
+
+# Set up a fully-qualified path name to the input script so that CASA can
+# always find it, even when we hop around in subdirectories. Otherwise it
+# tries to evaluate the filename as a line of Python.
+
+script=$(cd $(dirname $1) && pwd)/$(basename $1)
+if [ ! -e "$script" ] ; then
+    echo >&2 "error: cannot find input script \"$1\"; should be at \"$script\""
+    exit 1
+fi
+
+workdir=`mktemp -d casascript.XXXXXXXXX`
+cd "$workdir"
+ln -s .. data
+cp /proc/$$/cmdline args
+mkfifo csout cserr || exit 1
+
+# Process group management insanity:
+# http://stackoverflow.com/a/1645157/3760486 I'm sure I could do a
+# better/cleaner job of this, but I'm pretty sure this code errs on the side
+# of safety, and that's my priority.
+
+trap : SIGTERM SIGINT
+cat csout &
+killpids="-$!"
+cat cserr >&2 &
+killpids="$killpids -$!"
+casapy --log2term --nogui -c "$script" </dev/null >stdout 2>stderr &
+killpids="$killpids -$!"
+wait $!
+retval=$?
+
+if [ $retval -gt 128 ] ; then
+    kill -- $killpids
+fi
+
+if [ $retval -ne 0 ] ; then
+    echo >&2 "error: casapy exited with error code $retval; preserving work directory $workdir"
+else
+    cd ..
+    [ x"$CASASCRIPT_DEBUG_WORK" != x ] || rm -rf "$workdir"
+fi
+
+exit $retval
-- 
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