diff options
Diffstat (limited to 'Lib/pipes.py')
| -rw-r--r-- | Lib/pipes.py | 414 |
1 files changed, 207 insertions, 207 deletions
diff --git a/Lib/pipes.py b/Lib/pipes.py index 3aa1bf1..77a57e8 100644 --- a/Lib/pipes.py +++ b/Lib/pipes.py @@ -69,229 +69,229 @@ import string # Conversion step kinds -FILEIN_FILEOUT = 'ff' # Must read & write real files -STDIN_FILEOUT = '-f' # Must write a real file -FILEIN_STDOUT = 'f-' # Must read a real file -STDIN_STDOUT = '--' # Normal pipeline element -SOURCE = '.-' # Must be first, writes stdout -SINK = '-.' # Must be last, reads stdin +FILEIN_FILEOUT = 'ff' # Must read & write real files +STDIN_FILEOUT = '-f' # Must write a real file +FILEIN_STDOUT = 'f-' # Must read a real file +STDIN_STDOUT = '--' # Normal pipeline element +SOURCE = '.-' # Must be first, writes stdout +SINK = '-.' # Must be last, reads stdin stepkinds = [FILEIN_FILEOUT, STDIN_FILEOUT, FILEIN_STDOUT, STDIN_STDOUT, \ - SOURCE, SINK] + SOURCE, SINK] class Template: - """Class representing a pipeline template.""" - - def __init__(self): - """Template() returns a fresh pipeline template.""" - self.debugging = 0 - self.reset() - - def __repr__(self): - """t.__repr__() implements `t`.""" - return '<Template instance, steps=' + `self.steps` + '>' - - def reset(self): - """t.reset() restores a pipeline template to its initial state.""" - self.steps = [] - - def clone(self): - """t.clone() returns a new pipeline template with identical - initial state as the current one.""" - t = Template() - t.steps = self.steps[:] - t.debugging = self.debugging - return t - - def debug(self, flag): - """t.debug(flag) turns debugging on or off.""" - self.debugging = flag - - def append(self, cmd, kind): - """t.append(cmd, kind) adds a new step at the end.""" - if type(cmd) is not type(''): - raise TypeError, \ - 'Template.append: cmd must be a string' - if kind not in stepkinds: - raise ValueError, \ - 'Template.append: bad kind ' + `kind` - if kind == SOURCE: - raise ValueError, \ - 'Template.append: SOURCE can only be prepended' - if self.steps and self.steps[-1][1] == SINK: - raise ValueError, \ - 'Template.append: already ends with SINK' - if kind[0] == 'f' and not re.search('\$IN\b', cmd): - raise ValueError, \ - 'Template.append: missing $IN in cmd' - if kind[1] == 'f' and not re.search('\$OUT\b', cmd): - raise ValueError, \ - 'Template.append: missing $OUT in cmd' - self.steps.append((cmd, kind)) - - def prepend(self, cmd, kind): - """t.prepend(cmd, kind) adds a new step at the front.""" - if type(cmd) is not type(''): - raise TypeError, \ - 'Template.prepend: cmd must be a string' - if kind not in stepkinds: - raise ValueError, \ - 'Template.prepend: bad kind ' + `kind` - if kind == SINK: - raise ValueError, \ - 'Template.prepend: SINK can only be appended' - if self.steps and self.steps[0][1] == SOURCE: - raise ValueError, \ - 'Template.prepend: already begins with SOURCE' - if kind[0] == 'f' and not re.search('\$IN\b', cmd): - raise ValueError, \ - 'Template.prepend: missing $IN in cmd' - if kind[1] == 'f' and not re.search('\$OUT\b', cmd): - raise ValueError, \ - 'Template.prepend: missing $OUT in cmd' - self.steps.insert(0, (cmd, kind)) - - def open(self, file, rw): - """t.open(file, rw) returns a pipe or file object open for - reading or writing; the file is the other end of the pipeline.""" - if rw == 'r': - return self.open_r(file) - if rw == 'w': - return self.open_w(file) - raise ValueError, \ - 'Template.open: rw must be \'r\' or \'w\', not ' + `rw` - - def open_r(self, file): - """t.open_r(file) and t.open_w(file) implement - t.open(file, 'r') and t.open(file, 'w') respectively.""" - if not self.steps: - return open(file, 'r') - if self.steps[-1][1] == SINK: - raise ValueError, \ - 'Template.open_r: pipeline ends width SINK' - cmd = self.makepipeline(file, '') - return os.popen(cmd, 'r') - - def open_w(self, file): - if not self.steps: - return open(file, 'w') - if self.steps[0][1] == SOURCE: - raise ValueError, \ - 'Template.open_w: pipeline begins with SOURCE' - cmd = self.makepipeline('', file) - return os.popen(cmd, 'w') - - def copy(self, infile, outfile): - return os.system(self.makepipeline(infile, outfile)) - - def makepipeline(self, infile, outfile): - cmd = makepipeline(infile, self.steps, outfile) - if self.debugging: - print cmd - cmd = 'set -x; ' + cmd - return cmd + """Class representing a pipeline template.""" + + def __init__(self): + """Template() returns a fresh pipeline template.""" + self.debugging = 0 + self.reset() + + def __repr__(self): + """t.__repr__() implements `t`.""" + return '<Template instance, steps=' + `self.steps` + '>' + + def reset(self): + """t.reset() restores a pipeline template to its initial state.""" + self.steps = [] + + def clone(self): + """t.clone() returns a new pipeline template with identical + initial state as the current one.""" + t = Template() + t.steps = self.steps[:] + t.debugging = self.debugging + return t + + def debug(self, flag): + """t.debug(flag) turns debugging on or off.""" + self.debugging = flag + + def append(self, cmd, kind): + """t.append(cmd, kind) adds a new step at the end.""" + if type(cmd) is not type(''): + raise TypeError, \ + 'Template.append: cmd must be a string' + if kind not in stepkinds: + raise ValueError, \ + 'Template.append: bad kind ' + `kind` + if kind == SOURCE: + raise ValueError, \ + 'Template.append: SOURCE can only be prepended' + if self.steps and self.steps[-1][1] == SINK: + raise ValueError, \ + 'Template.append: already ends with SINK' + if kind[0] == 'f' and not re.search('\$IN\b', cmd): + raise ValueError, \ + 'Template.append: missing $IN in cmd' + if kind[1] == 'f' and not re.search('\$OUT\b', cmd): + raise ValueError, \ + 'Template.append: missing $OUT in cmd' + self.steps.append((cmd, kind)) + + def prepend(self, cmd, kind): + """t.prepend(cmd, kind) adds a new step at the front.""" + if type(cmd) is not type(''): + raise TypeError, \ + 'Template.prepend: cmd must be a string' + if kind not in stepkinds: + raise ValueError, \ + 'Template.prepend: bad kind ' + `kind` + if kind == SINK: + raise ValueError, \ + 'Template.prepend: SINK can only be appended' + if self.steps and self.steps[0][1] == SOURCE: + raise ValueError, \ + 'Template.prepend: already begins with SOURCE' + if kind[0] == 'f' and not re.search('\$IN\b', cmd): + raise ValueError, \ + 'Template.prepend: missing $IN in cmd' + if kind[1] == 'f' and not re.search('\$OUT\b', cmd): + raise ValueError, \ + 'Template.prepend: missing $OUT in cmd' + self.steps.insert(0, (cmd, kind)) + + def open(self, file, rw): + """t.open(file, rw) returns a pipe or file object open for + reading or writing; the file is the other end of the pipeline.""" + if rw == 'r': + return self.open_r(file) + if rw == 'w': + return self.open_w(file) + raise ValueError, \ + 'Template.open: rw must be \'r\' or \'w\', not ' + `rw` + + def open_r(self, file): + """t.open_r(file) and t.open_w(file) implement + t.open(file, 'r') and t.open(file, 'w') respectively.""" + if not self.steps: + return open(file, 'r') + if self.steps[-1][1] == SINK: + raise ValueError, \ + 'Template.open_r: pipeline ends width SINK' + cmd = self.makepipeline(file, '') + return os.popen(cmd, 'r') + + def open_w(self, file): + if not self.steps: + return open(file, 'w') + if self.steps[0][1] == SOURCE: + raise ValueError, \ + 'Template.open_w: pipeline begins with SOURCE' + cmd = self.makepipeline('', file) + return os.popen(cmd, 'w') + + def copy(self, infile, outfile): + return os.system(self.makepipeline(infile, outfile)) + + def makepipeline(self, infile, outfile): + cmd = makepipeline(infile, self.steps, outfile) + if self.debugging: + print cmd + cmd = 'set -x; ' + cmd + return cmd def makepipeline(infile, steps, outfile): - # Build a list with for each command: - # [input filename or '', command string, kind, output filename or ''] - - list = [] - for cmd, kind in steps: - list.append(['', cmd, kind, '']) - # - # Make sure there is at least one step - # - if not list: - list.append(['', 'cat', '--', '']) - # - # Take care of the input and output ends - # - [cmd, kind] = list[0][1:3] - if kind[0] == 'f' and not infile: - list.insert(0, ['', 'cat', '--', '']) - list[0][0] = infile - # - [cmd, kind] = list[-1][1:3] - if kind[1] == 'f' and not outfile: - list.append(['', 'cat', '--', '']) - list[-1][-1] = outfile - # - # Invent temporary files to connect stages that need files - # - garbage = [] - for i in range(1, len(list)): - lkind = list[i-1][2] - rkind = list[i][2] - if lkind[1] == 'f' or rkind[0] == 'f': - temp = tempfile.mktemp() - garbage.append(temp) - list[i-1][-1] = list[i][0] = temp - # - for item in list: - [inf, cmd, kind, outf] = item - if kind[1] == 'f': - cmd = 'OUT=' + quote(outf) + '; ' + cmd - if kind[0] == 'f': - cmd = 'IN=' + quote(inf) + '; ' + cmd - if kind[0] == '-' and inf: - cmd = cmd + ' <' + quote(inf) - if kind[1] == '-' and outf: - cmd = cmd + ' >' + quote(outf) - item[1] = cmd - # - cmdlist = list[0][1] - for item in list[1:]: - [cmd, kind] = item[1:3] - if item[0] == '': - if 'f' in kind: - cmd = '{ ' + cmd + '; }' - cmdlist = cmdlist + ' |\n' + cmd - else: - cmdlist = cmdlist + '\n' + cmd - # - if garbage: - rmcmd = 'rm -f' - for file in garbage: - rmcmd = rmcmd + ' ' + quote(file) - trapcmd = 'trap ' + quote(rmcmd + '; exit') + ' 1 2 3 13 14 15' - cmdlist = trapcmd + '\n' + cmdlist + '\n' + rmcmd - # - return cmdlist + # Build a list with for each command: + # [input filename or '', command string, kind, output filename or ''] + + list = [] + for cmd, kind in steps: + list.append(['', cmd, kind, '']) + # + # Make sure there is at least one step + # + if not list: + list.append(['', 'cat', '--', '']) + # + # Take care of the input and output ends + # + [cmd, kind] = list[0][1:3] + if kind[0] == 'f' and not infile: + list.insert(0, ['', 'cat', '--', '']) + list[0][0] = infile + # + [cmd, kind] = list[-1][1:3] + if kind[1] == 'f' and not outfile: + list.append(['', 'cat', '--', '']) + list[-1][-1] = outfile + # + # Invent temporary files to connect stages that need files + # + garbage = [] + for i in range(1, len(list)): + lkind = list[i-1][2] + rkind = list[i][2] + if lkind[1] == 'f' or rkind[0] == 'f': + temp = tempfile.mktemp() + garbage.append(temp) + list[i-1][-1] = list[i][0] = temp + # + for item in list: + [inf, cmd, kind, outf] = item + if kind[1] == 'f': + cmd = 'OUT=' + quote(outf) + '; ' + cmd + if kind[0] == 'f': + cmd = 'IN=' + quote(inf) + '; ' + cmd + if kind[0] == '-' and inf: + cmd = cmd + ' <' + quote(inf) + if kind[1] == '-' and outf: + cmd = cmd + ' >' + quote(outf) + item[1] = cmd + # + cmdlist = list[0][1] + for item in list[1:]: + [cmd, kind] = item[1:3] + if item[0] == '': + if 'f' in kind: + cmd = '{ ' + cmd + '; }' + cmdlist = cmdlist + ' |\n' + cmd + else: + cmdlist = cmdlist + '\n' + cmd + # + if garbage: + rmcmd = 'rm -f' + for file in garbage: + rmcmd = rmcmd + ' ' + quote(file) + trapcmd = 'trap ' + quote(rmcmd + '; exit') + ' 1 2 3 13 14 15' + cmdlist = trapcmd + '\n' + cmdlist + '\n' + rmcmd + # + return cmdlist # Reliably quote a string as a single argument for /bin/sh -_safechars = string.letters + string.digits + '!@%_-+=:,./' # Safe unquoted -_funnychars = '"`$\\' # Unsafe inside "double quotes" +_safechars = string.letters + string.digits + '!@%_-+=:,./' # Safe unquoted +_funnychars = '"`$\\' # Unsafe inside "double quotes" def quote(file): - for c in file: - if c not in _safechars: - break - else: - return file - if '\'' not in file: - return '\'' + file + '\'' - res = '' - for c in file: - if c in _funnychars: - c = '\\' + c - res = res + c - return '"' + res + '"' + for c in file: + if c not in _safechars: + break + else: + return file + if '\'' not in file: + return '\'' + file + '\'' + res = '' + for c in file: + if c in _funnychars: + c = '\\' + c + res = res + c + return '"' + res + '"' # Small test program and example def test(): - print 'Testing...' - t = Template() - t.append('togif $IN $OUT', 'ff') - t.append('giftoppm', '--') - t.append('ppmtogif >$OUT', '-f') - t.append('fromgif $IN $OUT', 'ff') - t.debug(1) - FILE = '/usr/local/images/rgb/rogues/guido.rgb' - t.copy(FILE, '@temp') - print 'Done.' + print 'Testing...' + t = Template() + t.append('togif $IN $OUT', 'ff') + t.append('giftoppm', '--') + t.append('ppmtogif >$OUT', '-f') + t.append('fromgif $IN $OUT', 'ff') + t.debug(1) + FILE = '/usr/local/images/rgb/rogues/guido.rgb' + t.copy(FILE, '@temp') + print 'Done.' |