Kaydet (Commit) 29bb115b authored tarafından Eric S. Raymond's avatar Eric S. Raymond

Clean up some argument profiles, enrich the docstring.

üst d0688ebc
...@@ -31,7 +31,7 @@ simply passed as the first argument to the transformation function. ...@@ -31,7 +31,7 @@ simply passed as the first argument to the transformation function.
Typically it is a string that names the filter and is used in Typically it is a string that names the filter and is used in
generating error messages, but it could be arbitrary data. generating error messages, but it could be arbitrary data.
The second argument, is interpreted as a list of filenames. The files The second argument is interpreted as a list of filenames. The files
are transformed in left to right order in the list. A filename are transformed in left to right order in the list. A filename
consisting of a dash is interpreted as a directive to read from consisting of a dash is interpreted as a directive to read from
standard input (this can be useful in pipelines). standard input (this can be useful in pipelines).
...@@ -59,27 +59,27 @@ translation of that file has completed. Any tempfiles are removed ...@@ -59,27 +59,27 @@ translation of that file has completed. Any tempfiles are removed
automatically on any exception thrown by the translation function, automatically on any exception thrown by the translation function,
and the exception is then passed upwards. and the exception is then passed upwards.
\begin{funcdesc}{filefilter}{name, arguments, trans_data\optional{,trans_file}} \begin{funcdesc}{filefilter}{name, file, arguments, trans_data\optional{,trans_file}}
Filter using a function taking the name and two file-object Filter using a function taking the name, filename, and two file-object
arguments. The function is expected to read data from the input file arguments. The function is expected to read data from the input file
object, transform it, and write the data to the output file object. object, transform it, and write the data to the output file object.
When the function terminates, the translation is done. The return When the function terminates, the translation is done. The return
value of the transformation function is not used. value of the transformation function is not used.
\end{funcdesc} \end{funcdesc}
\begin{funcdesc}{linefilter}{name,arguments,trans_data\optional{,trans_file}} \begin{funcdesc}{linefilter}{name, file, arguments,trans_data\optional{,trans_file}}
Filter using a function taking the name and a string argument. The return Filter using a function taking the name, the filename, and a string
value of the function should be a string. This function is applied to argument. The return value of the function should be a string. This
each line in the input file in turn; the return values become the function is applied to each line in the input file in turn; the return
lines of the transformed file. values become the lines of the transformed file.
\end{funcdesc} \end{funcdesc}
\begin{funcdesc}{sponge}{name, arguments, trans_data\optional{, trans_file}} \begin{funcdesc}{sponge}{name, file, arguments, trans_data\optional{, trans_file}}
Filter using a function taking the name and a string argument. The Filter using a function taking the name, the filename, and a string
return value of the function should be a string. The function will be argument. The return value of the function should be a string. The
passed the entire contents of the input file as a string. The string function will be passed the entire contents of the input file as a
return value of the function will become the entire contents of the string. The string return value of the function will become the
transformed file. entire contents of the transformed file.
\end{funcdesc} \end{funcdesc}
# End # End
......
...@@ -7,12 +7,23 @@ behaves as a filter when no argument files are specified on the command ...@@ -7,12 +7,23 @@ behaves as a filter when no argument files are specified on the command
line, but otherwise transforms each file individually into a corresponding line, but otherwise transforms each file individually into a corresponding
output file. output file.
This module provides framework and glue code to make such programs easy This module provides framework and glue code to make such programs
to write. You supply a function to massage the file data; depending easy to write. You supply a function to massage the file data. It
on which entry point you use, it can take input and output file pointers, always takes initial name and filename arguments; depending on which
or it can take a string consisting of the entire file's data and return entry point you use, it can also take input and output file pointers,
a replacement, or it can take in succession strings consisting of each or it can take a string consisting of the entire file's data and
of the file's lines and return a translated line for each. return a replacement, or it can take in succession strings consisting
of each of the file's lines and return a translated line for each.
The fourth, optional argument of each entry point is a name
transformation function or name suffix string. If it is of string
type, the shortest suffix of each filename beginning with the first
character of the argument string is stripped off. If the first
character of the argument does not occur in the filename, no suffix is
removed. Then the name suffix argument is concatenated to the end of
the stripped filename. (Thus, a name suffix argument of ".x" will
cause the filenames foo.c and bar.d to be transformed to foo.x and
bar.x respectively.)
Argument files are transformed in left to right order in the argument list. Argument files are transformed in left to right order in the argument list.
A filename consisting of a dash is interpreted as a directive to read from A filename consisting of a dash is interpreted as a directive to read from
...@@ -25,14 +36,12 @@ and the exception is then passed upwards. ...@@ -25,14 +36,12 @@ and the exception is then passed upwards.
""" """
# Requires Python 2. # Requires Python 2.
from __future__ import nested_scopes
import sys, os, filecmp, traceback import sys, os, filecmp, traceback
def filefilter(name, arguments, trans_data, trans_filename=None): def filefilter(name, arguments, trans_data, trans_filename=None):
"Filter stdin to stdout, or file arguments to renamed files." "Filter stdin to stdout, or file arguments to renamed files."
if not arguments: if not arguments:
trans_data("stdin", sys.stdin, sys.stdout) trans_data(name, "stdin", sys.stdin, sys.stdout)
else: else:
for file in arguments: for file in arguments:
if file == '-': # - is conventional for stdin if file == '-': # - is conventional for stdin
...@@ -43,7 +52,7 @@ def filefilter(name, arguments, trans_data, trans_filename=None): ...@@ -43,7 +52,7 @@ def filefilter(name, arguments, trans_data, trans_filename=None):
tempfile = file + ".~%s-%d~" % (name, os.getpid()) tempfile = file + ".~%s-%d~" % (name, os.getpid())
outfp = open(tempfile, "w") outfp = open(tempfile, "w")
try: try:
trans_data(file, infp, outfp) trans_data(name, file, infp, outfp)
except: except:
os.remove(tempfile) os.remove(tempfile)
# Pass the exception upwards # Pass the exception upwards
...@@ -62,26 +71,26 @@ def filefilter(name, arguments, trans_data, trans_filename=None): ...@@ -62,26 +71,26 @@ def filefilter(name, arguments, trans_data, trans_filename=None):
else: else:
os.rename(tempfile, trans_filename(file)) os.rename(tempfile, trans_filename(file))
def line_by_line(name, infp, outfp, translate_line): def line_by_line(name, file, infp, outfp, translate_line):
"Hook to do line-by-line translation for filters." "Hook to do line-by-line translation for filters."
while 1: while 1:
line = infp.readline() line = infp.readline()
if line == "": if line == "":
break break
elif line: # None returns are skipped elif line: # None returns are skipped
outfp.write(translate_line(name, line)) outfp.write(translate_line(name, file, line))
def linefilter(name, arguments, trans_data, trans_filename=None): def linefilter(name, arguments, trans_data, trans_filename=None):
"Filter framework for line-by-line transformation." "Filter framework for line-by-line transformation."
return filefilter(name, return filefilter(name,
arguments, arguments,
lambda name, infp, outfp: line_by_line(name, infp, outfp, trans_data), lambda name, file, infp, outfp: line_by_line(name, file, infp, outfp, trans_data),
trans_filename) trans_filename)
def sponge(name, arguments, trans_data, trans_filename=None): def sponge(name, arguments, trans_data, trans_filename=None):
"Read input sources entire and transform them in memory." "Read input sources entire and transform them in memory."
if not arguments: if not arguments:
sys.stdout.write(trans_data(name, sys.stdin.read())) sys.stdout.write(trans_data(name, "stdin", sys.stdin.read()))
else: else:
for file in arguments: for file in arguments:
infp = open(file) infp = open(file)
...@@ -94,7 +103,7 @@ def sponge(name, arguments, trans_data, trans_filename=None): ...@@ -94,7 +103,7 @@ def sponge(name, arguments, trans_data, trans_filename=None):
sys.stderr.write("%s: can't open tempfile" % name) sys.stderr.write("%s: can't open tempfile" % name)
return 1 return 1
try: try:
outdoc = trans_data(name, indoc) outdoc = trans_data(name, file, indoc)
except: except:
os.remove(tempfile) os.remove(tempfile)
# Pass the exception upwards # Pass the exception upwards
...@@ -120,7 +129,7 @@ if __name__ == '__main__': ...@@ -120,7 +129,7 @@ if __name__ == '__main__':
def nametrans(name): def nametrans(name):
return name + ".out" return name + ".out"
def filefilter_test(name, infp, outfp): def filefilter_test(name, file, infp, outfp):
"Test hook for filefilter entry point -- put dashes before blank lines." "Test hook for filefilter entry point -- put dashes before blank lines."
while 1: while 1:
line = infp.readline() line = infp.readline()
...@@ -130,11 +139,11 @@ if __name__ == '__main__': ...@@ -130,11 +139,11 @@ if __name__ == '__main__':
outfp.write("------------------------------------------\n") outfp.write("------------------------------------------\n")
outfp.write(line) outfp.write(line)
def linefilter_test(name, data): def linefilter_test(name, file, data):
"Test hook for linefilter entry point -- wrap lines in brackets." "Test hook for linefilter entry point -- wrap lines in brackets."
return "<" + data[:-1] + ">\n" return "<" + data[:-1] + ">\n"
def sponge_test(name, data): def sponge_test(name, file, data):
"Test hook for the sponge entry point -- reverse file lines." "Test hook for the sponge entry point -- reverse file lines."
lines = data.split("\n") lines = data.split("\n")
lines.reverse() lines.reverse()
......
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