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mhammondmhammond
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Fix bugs:
 457466: popenx() argument mangling hangs python 226766: popen('python -c"...."') tends to hang Fixes argument quoting in w9xpopen.exe for Windows 9x. w9xpopen.exe also never attempts to display a MessageBox when not executed interactively. Added test_popen() test. This test currently just executes "python -c ..." as a child process, and checks that the expected arguments were all recieved correctly by the child process. This test succeeds for me on Win9x, win2k and Linux, and I hope it does for other popen supported platforms too :)
1 parent b0aaec5 commit e7fefbf

4 files changed

Lines changed: 98 additions & 5 deletions

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‎Lib/test/output/test_popen‎

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,3 @@
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test_popen
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Test popen:
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popen seemed to process the command-line correctly

‎Lib/test/test_popen.py‎

Lines changed: 36 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,36 @@
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#! /usr/bin/env python
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"""Basic tests for os.popen()
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Particularly useful for platforms that fake popen.
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"""
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import os
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import sys
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from test_support import TestSkipped
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from os import popen
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# Test that command-lines get down as we expect.
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# To do this we execute:
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# python -c "import sys;print sys.argv" {rest_of_commandline}
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# This results in Python being spawned and printing the sys.argv list.
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# We can then eval() the result of this, and see what each argv was.
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def _do_test_commandline(cmdline, expected):
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cmd = 'python -c "import sys;print sys.argv" %s' % (cmdline,)
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data = popen(cmd).read()
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got = eval(data)[1:] # strip off argv[0]
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if got != expected:
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print "Error in popen commandline handling."
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print " executed '%s', expected '%r', but got '%r'" \
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% (cmdline, expected, got)
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def _test_commandline():
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_do_test_commandline("foo bar", ["foo", "bar"])
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_do_test_commandline('foo "spam and eggs" "silly walk"', ["foo", "spam and eggs", "silly walk"])
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_do_test_commandline('foo "a \\"quoted\\" arg" bar', ["foo", 'a "quoted" arg', "bar"])
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print "popen seemed to process the command-line correctly"
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def main():
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print "Test popen:"
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_test_commandline()
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main()

‎Modules/posixmodule.c‎

Lines changed: 7 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -3285,9 +3285,15 @@ _PyPopenCreateProcess(char *cmdstring,
32853285

32863286
s2 = (char *)_alloca(x);
32873287
ZeroMemory(s2, x);
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/* To maintain correct argument passing semantics,
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we pass the command-line as it stands, and allow
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quoting to be applied. w9xpopen.exe will then
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use its argv vector, and re-quote the necessary
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args for the ultimate child process.
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*/
32883294
PyOS_snprintf(
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s2, x,
3290-
"%s \"%s%s%s\"",
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"\"%s\" %s%s%s",
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modulepath,
32923298
s1,
32933299
s3,

‎PC/w9xpopen.c‎

Lines changed: 52 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -16,9 +16,10 @@
1616

1717
#define WINDOWS_LEAN_AND_MEAN
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#include <windows.h>
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#include <stdio.h>
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const char *usage =
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"This program is used by Python's os.pipe function to\n"
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"This program is used by Python's os.popen function to\n"
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"to work around a limitation in Windows 95/98. It is\n"
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"not designed to be used as stand-alone program.";
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@@ -28,11 +29,56 @@ int main(int argc, char *argv[])
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STARTUPINFO si;
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PROCESS_INFORMATION pi;
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DWORD exit_code=0;
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int cmdlen = 0;
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int i;
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char *cmdline, *cmdlinefill;
3135

32-
if (argc != 2) {
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MessageBox(NULL, usage, argv[0], MB_OK);
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if (argc < 2) {
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if (GetFileType(GetStdHandle(STD_INPUT_HANDLE))==FILE_TYPE_CHAR)
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/* Attached to a console, and therefore not executed by Python
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Display a message box for the inquisitive user
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*/
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MessageBox(NULL, usage, argv[0], MB_OK);
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else {
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/* Eeek - executed by Python, but args are screwed!
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Write an error message to stdout so there is at
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least some clue for the end user when it appears
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in their output.
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A message box would be hidden and blocks the app.
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*/
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fprintf(stdout, "Internal popen error - no args specified\n%s\n", usage);
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}
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return 1;
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}
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/* Build up the command-line from the args.
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Args with a space are quoted, existing quotes are escaped.
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To keep things simple calculating the buffer size, we assume
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every character is a quote - ie, we allocate double what we need
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in the worst case. As this is only double the command line passed
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to us, there is a good chance this is reasonably small, so the total
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allocation will almost always be < 512 bytes.
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*/
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for (i=1;i<argc;i++)
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cmdlen += strlen(argv[i])*2 + 3; /* one space, maybe 2 quotes */
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cmdline = cmdlinefill = (char *)malloc(cmdlen+1);
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if (cmdline == NULL)
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return -1;
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for (i=1;i<argc;i++) {
67+
const char *arglook;
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int bQuote = strchr(argv[i], ' ') != NULL;
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if (bQuote)
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*cmdlinefill++ = '"';
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/* escape quotes */
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for (arglook=argv[i];*arglook;arglook++) {
73+
if (*arglook=='"')
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*cmdlinefill++ = '\\';
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*cmdlinefill++ = *arglook;
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}
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if (bQuote)
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*cmdlinefill++ = '"';
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*cmdlinefill++ = ' ';
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}
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*cmdlinefill = '\0';
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3783
/* Make child process use this app's standard files. */
3884
ZeroMemory(&si, sizeof si);
@@ -43,13 +89,15 @@ int main(int argc, char *argv[])
4389
si.hStdError = GetStdHandle(STD_ERROR_HANDLE);
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4591
bRet = CreateProcess(
46-
NULL, argv[1],
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NULL, cmdline,
4793
NULL, NULL,
4894
TRUE, 0,
4995
NULL, NULL,
5096
&si, &pi
5197
);
5298

99+
free(cmdline);
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53101
if (bRet) {
54102
if (WaitForSingleObject(pi.hProcess, INFINITE) != WAIT_FAILED) {
55103
GetExitCodeProcess(pi.hProcess, &exit_code);

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