B.2.8 System

Functions for executing shell commands on the local operating system and other system-level operations.

exec( words, ... )

Executes an operating system command composed of a command and one or more arguments.

Each of the words values is treated as a single (possibly quoted) word in a shell command. The first argument is the filename (either a full pathname, or the name of a file on the current path) of an executable file. These values can be numeric, or strings, or something else, and are converted automatically to string values.

• Parameters:
  • words (Object, one or more): one or more words composing a shell command; first is command and others are arguments
• Return value
  • (String): short report message
• Examples:
  • exec("/home/mbt/bin/process_obj.py", OBJ_NAME)
  • exec("process_skycoords.py", RA, DEC)
  • exec("process_sphericalcoords.sh", RA, DEC, 1.0)

exec( line )

Executes a string as an operating system command. Any spaces in the string are taken to delimit words (the first word is the name of the command).

• Parameters:
  • line (String): command line to execute
• Return value
  • (String): short report message
• Example:
  • exec("do_stuff.py " + RA + " " + DEC)

sleepMillis( millis )

Waits for a specified number of milliseconds.

• Parameters:
  • millis (integer): number of milliseconds to wait

sleep( secs )

Waits for a specified number of seconds.

• Parameters:
  • secs (integer): number of seconds to wait