Re: [Tutor] Problem with os.access function. [semantic error, if check does not work]
Hello, Thank you both for the tip's and the interesting links. I resolved my problem easily using another function, os.path.isdir(x) which was more specific. Best Regards. On 12/24/05, bob <[EMAIL PROTECTED]> wrote: > At 05:20 AM 12/24/2005, Panagiotis Atmatzidis wrote: > >Hello, > > > >I am writing a function in order to check if a directory exists. If > >exists the functions must do nothing, otherwise must check the users > >permissions and if it's possible create the dir. Looking at pydoc's > >httpd I found the module "os" and the function "access". From the > >http-doc: > > > >access(...) > >access(path, mode) -> 1 if granted, 0 otherwise > > > >Use the real uid/gid to test for access to a path. Note that most > >operations will use the effective uid/gid, therefore this routine can > >be used in a suid/sgid environment to test if the invoking user has the > >specified access to the path. The mode argument can be F_OK to test > >existence, or the inclusive-OR of R_OK, W_OK, and X_OK. > > > >This is my function: > > > >def homedirhandle(): > > path = "/some/dir/" # check the existance of the > >directory > > mode = 755 > > should be mode = 0755 (octal representation) for mkdir. For > access: "The mode argument can be F_OK to test existence, or the > inclusive-OR of R_OK, W_OK, and X_OK." suggests that only 1 digit is expected. > > > check_path = os.access(path, mode) > > print check_path > > if check_path == 'False': > > Should be if check_path == False: > > Or even simpler if not check_path: > > Use print repr(check_path). Then you'd see either True or 'True'. > That would help you see whether check_path is boolean or string. > > > print "" > > print "Directory /some/dir does not exist." > > print "Trying to create the directory." > > uid = os.geteuid() > > print "the uid is ", uid > > if uid == '0': > > I think (not having UNIX access at the moment) that this should be if uid == > 0: > > > try: > >os.mkdir(path, mode) > >print "" > >print "The directory has been created." > >print "" > >return path > > except OSError, e: > > print "" > > print >>sys.stderr, "The mkdir command failed: > >%d (%s)" % (e.errno, e.strerror) > > print "" > > print "Exiting" > > sys.exit(1) > > > > if check_path == '1': > > == 1 > > > print "" > > print "The directory /some/dir has been created." > > print "" > > return path > > else: > > print "Please create the directory /some/dir manually and > >then re-run vuhalndler." > > print "Exiting" > > sys.exit() > > else: > > print "" > > print "The directory already exists." > > print "" > > return path > > > >Now the problem lies at the first check " if check_path == 'False': > >". It's a semantic error, the program does not really check the dir, > >it just takes for granted that the dir exists. I tried with 1 before > >putting "False" there.. but it did not work so I took the print result > >of check_path and substitute 1 with False. But still nothing :-( > > > >Why does not make the check? I thought that the functions > >functionality was clear.. probably is not. > > > > > > > >-- > >Panagiotis > >___ > >Tutor maillist - Tutor@python.org > >http://mail.python.org/mailman/listinfo/tutor > > -- Panagiotis ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Problem with os.access function. [semantic error, if check does not work]
Take a look at my draft OS topic(click the url below). It will point you at several other functions that will be of use... Alan G Author of the learn to program web tutor http://www.freenetpages.co.uk/hp/alan.gauld/tutos.htm - Original Message - From: "Panagiotis Atmatzidis" <[EMAIL PROTECTED]> To: "Python Tutor" Sent: Saturday, December 24, 2005 1:20 PM Subject: [Tutor] Problem with os.access function. [semantic error,if check does not work] Hello, I am writing a function in order to check if a directory exists. If exists the functions must do nothing, otherwise must check the users permissions and if it's possible create the dir. Looking at pydoc's httpd I found the module "os" and the function "access". From the http-doc: access(...) access(path, mode) -> 1 if granted, 0 otherwise Use the real uid/gid to test for access to a path. Note that most operations will use the effective uid/gid, therefore this routine can be used in a suid/sgid environment to test if the invoking user has the specified access to the path. The mode argument can be F_OK to test existence, or the inclusive-OR of R_OK, W_OK, and X_OK. This is my function: def homedirhandle(): path = "/some/dir/" # check the existance of the directory mode = 755 check_path = os.access(path, mode) print check_path if check_path == 'False': print "" print "Directory /some/dir does not exist." print "Trying to create the directory." uid = os.geteuid() print "the uid is ", uid if uid == '0': try: os.mkdir(path, mode) print "" print "The directory has been created." print "" return path except OSError, e: print "" print >>sys.stderr, "The mkdir command failed: %d (%s)" % (e.errno, e.strerror) print "" print "Exiting" sys.exit(1) if check_path == '1': print "" print "The directory /some/dir has been created." print "" return path else: print "Please create the directory /some/dir manually and then re-run vuhalndler." print "Exiting" sys.exit() else: print "" print "The directory already exists." print "" return path Now the problem lies at the first check " if check_path == 'False': ". It's a semantic error, the program does not really check the dir, it just takes for granted that the dir exists. I tried with 1 before putting "False" there.. but it did not work so I took the print result of check_path and substitute 1 with False. But still nothing :-( Why does not make the check? I thought that the functions functionality was clear.. probably is not. -- Panagiotis ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Problem with os.access function. [semantic error, if check does not work]
At 05:20 AM 12/24/2005, Panagiotis Atmatzidis wrote: >Hello, > >I am writing a function in order to check if a directory exists. If >exists the functions must do nothing, otherwise must check the users >permissions and if it's possible create the dir. Looking at pydoc's >httpd I found the module "os" and the function "access". From the >http-doc: > >access(...) >access(path, mode) -> 1 if granted, 0 otherwise > >Use the real uid/gid to test for access to a path. Note that most >operations will use the effective uid/gid, therefore this routine can >be used in a suid/sgid environment to test if the invoking user has the >specified access to the path. The mode argument can be F_OK to test >existence, or the inclusive-OR of R_OK, W_OK, and X_OK. > >This is my function: > >def homedirhandle(): > path = "/some/dir/" # check the existance of the >directory > mode = 755 should be mode = 0755 (octal representation) for mkdir. For access: "The mode argument can be F_OK to test existence, or the inclusive-OR of R_OK, W_OK, and X_OK." suggests that only 1 digit is expected. > check_path = os.access(path, mode) > print check_path > if check_path == 'False': Should be if check_path == False: Or even simpler if not check_path: Use print repr(check_path). Then you'd see either True or 'True'. That would help you see whether check_path is boolean or string. > print "" > print "Directory /some/dir does not exist." > print "Trying to create the directory." > uid = os.geteuid() > print "the uid is ", uid > if uid == '0': I think (not having UNIX access at the moment) that this should be if uid == 0: > try: >os.mkdir(path, mode) >print "" >print "The directory has been created." >print "" >return path > except OSError, e: > print "" > print >>sys.stderr, "The mkdir command failed: >%d (%s)" % (e.errno, e.strerror) > print "" > print "Exiting" > sys.exit(1) > > if check_path == '1': == 1 > print "" > print "The directory /some/dir has been created." > print "" > return path > else: > print "Please create the directory /some/dir manually and >then re-run vuhalndler." > print "Exiting" > sys.exit() > else: > print "" > print "The directory already exists." > print "" > return path > >Now the problem lies at the first check " if check_path == 'False': >". It's a semantic error, the program does not really check the dir, >it just takes for granted that the dir exists. I tried with 1 before >putting "False" there.. but it did not work so I took the print result >of check_path and substitute 1 with False. But still nothing :-( > >Why does not make the check? I thought that the functions >functionality was clear.. probably is not. > > > >-- >Panagiotis >___ >Tutor maillist - Tutor@python.org >http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
