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      1 #! /usr/bin/env python

      2 
      3 # Emulate some Perl command line options.

      4 # Usage: pp [-a] [-c] [-d] [-e scriptline] [-F fieldsep] [-n] [-p] [file] ...

      5 # Where the options mean the following:

      6 #   -a            : together with -n or -p, splits each line into list F

      7 #   -c            : check syntax only, do not execute any code

      8 #   -d            : run the script under the debugger, pdb

      9 #   -e scriptline : gives one line of the Python script; may be repeated

     10 #   -F fieldsep   : sets the field separator for the -a option [not in Perl]

     11 #   -n            : runs the script for each line of input

     12 #   -p            : prints the line after the script has run

     13 # When no script lines have been passed, the first file argument

     14 # contains the script.  With -n or -p, the remaining arguments are

     15 # read as input to the script, line by line.  If a file is '-'

     16 # or missing, standard input is read.

     17 
     18 # XXX To do:

     19 # - add -i extension option (change files in place)

     20 # - make a single loop over the files and lines (changes effect of 'break')?

     21 # - add an option to specify the record separator

     22 # - except for -n/-p, run directly from the file if at all possible

     23 
     24 import sys
     25 import getopt
     26 
     27 FS = ''
     28 SCRIPT = []
     29 AFLAG = 0
     30 CFLAG = 0
     31 DFLAG = 0
     32 NFLAG = 0
     33 PFLAG = 0
     34 
     35 try:
     36     optlist, ARGS = getopt.getopt(sys.argv[1:], 'acde:F:np')
     37 except getopt.error, msg:
     38     sys.stderr.write('%s: %s\n' % (sys.argv[0], msg))
     39     sys.exit(2)
     40 
     41 for option, optarg in optlist:
     42     if option == '-a':
     43         AFLAG = 1
     44     elif option == '-c':
     45         CFLAG = 1
     46     elif option == '-d':
     47         DFLAG = 1
     48     elif option == '-e':
     49         for line in optarg.split('\n'):
     50             SCRIPT.append(line)
     51     elif option == '-F':
     52         FS = optarg
     53     elif option == '-n':
     54         NFLAG = 1
     55         PFLAG = 0
     56     elif option == '-p':
     57         NFLAG = 1
     58         PFLAG = 1
     59     else:
     60         print option, 'not recognized???'
     61 
     62 if not ARGS: ARGS.append('-')
     63 
     64 if not SCRIPT:
     65     if ARGS[0] == '-':
     66         fp = sys.stdin
     67     else:
     68         fp = open(ARGS[0], 'r')
     69     while 1:
     70         line = fp.readline()
     71         if not line: break
     72         SCRIPT.append(line[:-1])
     73     del fp
     74     del ARGS[0]
     75     if not ARGS: ARGS.append('-')
     76 
     77 if CFLAG:
     78     prologue = ['if 0:']
     79     epilogue = []
     80 elif NFLAG:
     81     # Note that it is on purpose that AFLAG and PFLAG are

     82     # tested dynamically each time through the loop

     83     prologue = [
     84             'LINECOUNT = 0',
     85             'for FILE in ARGS:',
     86             '   \tif FILE == \'-\':',
     87             '   \t   \tFP = sys.stdin',
     88             '   \telse:',
     89             '   \t   \tFP = open(FILE, \'r\')',
     90             '   \tLINENO = 0',
     91             '   \twhile 1:',
     92             '   \t   \tLINE = FP.readline()',
     93             '   \t   \tif not LINE: break',
     94             '   \t   \tLINENO = LINENO + 1',
     95             '   \t   \tLINECOUNT = LINECOUNT + 1',
     96             '   \t   \tL = LINE[:-1]',
     97             '   \t   \taflag = AFLAG',
     98             '   \t   \tif aflag:',
     99             '   \t   \t   \tif FS: F = L.split(FS)',
    100             '   \t   \t   \telse: F = L.split()'
    101             ]
    102     epilogue = [
    103             '   \t   \tif not PFLAG: continue',
    104             '   \t   \tif aflag:',
    105             '   \t   \t   \tif FS: print FS.join(F)',
    106             '   \t   \t   \telse: print \' \'.join(F)',
    107             '   \t   \telse: print L',
    108             ]
    109 else:
    110     prologue = ['if 1:']
    111     epilogue = []
    112 
    113 # Note that we indent using tabs only, so that any indentation style

    114 # used in 'command' will come out right after re-indentation.

    115 
    116 program = '\n'.join(prologue) + '\n'
    117 for line in SCRIPT:
    118     program += '   \t   \t' + line + '\n'
    119 program += '\n'.join(epilogue) + '\n'
    120 
    121 import tempfile
    122 fp = tempfile.NamedTemporaryFile()
    123 fp.write(program)
    124 fp.flush()
    125 if DFLAG:
    126     import pdb
    127     pdb.run('execfile(%r)' % (fp.name,))
    128 else:
    129     execfile(fp.name)
    130