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# psax.py; illustration of curses library
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# runs the shell command ps ax and saves the last lines of its output,
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# as many as the window will fit; allows the user to move up and down
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# within the window, killing those processes
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move highlight up a line
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move highlight down a line
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kill process in currently highlighted line
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re-run 'ps ax' for update
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# possible extensions: allowing scrolling, so that the user could go
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# through all the ps ax output; allow wraparound for long lines; ask
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# user to confirm before killing a process
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import curses, os, sys, traceback
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scrn = None # will point to Curses window object
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cmdoutlines = [] # output of 'ps ax' (including the lines we don't
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# use, for possible future extension)
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winrow = None # current row position in screen
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startrow = None # index of first row in cmdoutlines to be displayed
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p = os.popen('ps ax','r')
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# don't allow line wraparound, so truncate long lines
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# remove EOLN if it is still there
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if ln[-1] == '\n': ln = ln[:-1]
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gb.cmdoutlines.append(ln)
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# display last part of command output (as much as fits in screen)
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# prepare to paint the (last part of the) 'ps ax' output on the screen
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ncmdlines = len(gb.cmdoutlines)
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# two cases, depending on whether there is more output than screen rows
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if ncmdlines <= curses.LINES:
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gb.startrow = ncmdlines - curses.LINES - 1
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nwinlines = curses.LINES
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lastrow = gb.startrow + nwinlines - 1
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for ln in gb.cmdoutlines[gb.startrow:lastrow]:
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gb.scrn.addstr(gb.winrow,0,ln)
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# last line highlighted
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gb.scrn.addstr(gb.winrow,0,gb.cmdoutlines[lastrow],curses.A_BOLD)
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# move highlight up/down one line
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# ignore attempts to go off the edge of the screen
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if tmp >= 0 and tmp < curses.LINES:
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# unhighlight the current line by rewriting it in default attributes
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gb.scrn.addstr(gb.winrow,0,gb.cmdoutlines[gb.startrow+gb.winrow])
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# highlight the previous/next line
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ln = gb.cmdoutlines[gb.startrow+gb.winrow]
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gb.scrn.addstr(gb.winrow,0,ln,curses.A_BOLD)
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# kill the highlighted process
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ln = gb.cmdoutlines[gb.startrow+gb.winrow]
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pid = int(ln.split()[0])
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gb.scrn = curses.initscr()
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# rpdb.set_trace() (I used RPDB for debugging)
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# run 'ps ax' and process the output
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# display in the window
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if c == 'u': updown(-1)
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elif c == 'd': updown(1)
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elif c == 'r': rerun()
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elif c == 'k': kill()
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if __name__ =='__main__':
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# print error message re exception
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traceback.print_exc()
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removed
comps.drafts.builds/test.py
