cpython/Demo/scripts/pp.py
2007-08-12 00:43:29 +00:00

132 lines
3.9 KiB
Python
Executable File

#! /usr/bin/env python
# Emulate some Perl command line options.
# Usage: pp [-a] [-c] [-d] [-e scriptline] [-F fieldsep] [-n] [-p] [file] ...
# Where the options mean the following:
# -a : together with -n or -p, splits each line into list F
# -c : check syntax only, do not execute any code
# -d : run the script under the debugger, pdb
# -e scriptline : gives one line of the Python script; may be repeated
# -F fieldsep : sets the field separator for the -a option [not in Perl]
# -n : runs the script for each line of input
# -p : prints the line after the script has run
# When no script lines have been passed, the first file argument
# contains the script. With -n or -p, the remaining arguments are
# read as input to the script, line by line. If a file is '-'
# or missing, standard input is read.
# XXX To do:
# - add -i extension option (change files in place)
# - make a single loop over the files and lines (changes effect of 'break')?
# - add an option to specify the record separator
# - except for -n/-p, run directly from the file if at all possible
import sys
import string
import getopt
FS = ''
SCRIPT = []
AFLAG = 0
CFLAG = 0
DFLAG = 0
NFLAG = 0
PFLAG = 0
try:
optlist, ARGS = getopt.getopt(sys.argv[1:], 'acde:F:np')
except getopt.error as msg:
sys.stderr.write(sys.argv[0] + ': ' + msg + '\n')
sys.exit(2)
for option, optarg in optlist:
if option == '-a':
AFLAG = 1
elif option == '-c':
CFLAG = 1
elif option == '-d':
DFLAG = 1
elif option == '-e':
for line in string.splitfields(optarg, '\n'):
SCRIPT.append(line)
elif option == '-F':
FS = optarg
elif option == '-n':
NFLAG = 1
PFLAG = 0
elif option == '-p':
NFLAG = 1
PFLAG = 1
else:
print(option, 'not recognized???')
if not ARGS: ARGS.append('-')
if not SCRIPT:
if ARGS[0] == '-':
fp = sys.stdin
else:
fp = open(ARGS[0], 'r')
while 1:
line = fp.readline()
if not line: break
SCRIPT.append(line[:-1])
del fp
del ARGS[0]
if not ARGS: ARGS.append('-')
if CFLAG:
prologue = ['if 0:']
epilogue = []
elif NFLAG:
# Note that it is on purpose that AFLAG and PFLAG are
# tested dynamically each time through the loop
prologue = [ \
'LINECOUNT = 0', \
'for FILE in ARGS:', \
' \tif FILE == \'-\':', \
' \t \tFP = sys.stdin', \
' \telse:', \
' \t \tFP = open(FILE, \'r\')', \
' \tLINENO = 0', \
' \twhile 1:', \
' \t \tLINE = FP.readline()', \
' \t \tif not LINE: break', \
' \t \tLINENO = LINENO + 1', \
' \t \tLINECOUNT = LINECOUNT + 1', \
' \t \tL = LINE[:-1]', \
' \t \taflag = AFLAG', \
' \t \tif aflag:', \
' \t \t \tif FS: F = string.splitfields(L, FS)', \
' \t \t \telse: F = string.split(L)' \
]
epilogue = [ \
' \t \tif not PFLAG: continue', \
' \t \tif aflag:', \
' \t \t \tif FS: print string.joinfields(F, FS)', \
' \t \t \telse: print string.join(F)', \
' \t \telse: print L', \
]
else:
prologue = ['if 1:']
epilogue = []
# Note that we indent using tabs only, so that any indentation style
# used in 'command' will come out right after re-indentation.
program = string.joinfields(prologue, '\n') + '\n'
for line in SCRIPT:
program = program + (' \t \t' + line + '\n')
program = program + (string.joinfields(epilogue, '\n') + '\n')
import tempfile
fp = tempfile.NamedTemporaryFile()
fp.write(program)
fp.flush()
script = open(tfn).read()
if DFLAG:
import pdb
pdb.run(script)
else:
exec(script)