how to catch error with system()

[eight02645999]

hi

i have a piece of python code extract that calls an external java
program
cmd = """java someclass someargs"""
try:
ret = os.WEXITSTATUS(os.system(cmd))
except:
print blah
else:
dosomething(ret)

the thing is, the java class "someclass" produces it's own errors when
something goes wrong.
something like
java.io.FileNotFoundException: somefile (No such file or directory)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:106)
at java.io.FileInputStream.<init>(FileInputStream.java:66)
......

how can i supress this error from showing when i execute
../pythonscript.py and at the same time logging it to an errlog file??

thanks

 

[Diez B. Roggisch]

hi

i have a piece of python code extract that calls an external java
program
cmd = """java someclass someargs"""
try:
ret = os.WEXITSTATUS(os.system(cmd))
except:
print blah
else:
dosomething(ret)

the thing is, the java class "someclass" produces it's own errors when
something goes wrong.
something like
java.io.FileNotFoundException: somefile (No such file or directory)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:106)
at java.io.FileInputStream.<init>(FileInputStream.java:66)
......

how can i supress this error from showing when i execute
./pythonscript.py and at the same time logging it to an errlog file??

You probably want to catche the subprocesses stdout/stderr streams. To do
so, use the subprocess module (if you are on python2.4), or the
popen2-module. See the docs for how to use them.