Here’s what the C standard (n1256) says: 5.1.2.2.1 Program startup… 2 If they are declared, the parameters to the main function shall obey the following constraints: The value of argc shall be nonnegative. argv[argc] shall be a null pointer. If the value of argc is greater than zero, the array members argv[0] through argv[argc-1] inclusive … Read more
These methods are suited for servers with a lot of java processes running, and where you need a quick way of finding the correct jvm (not using jps.) For applications, I suppose launch4j or another wrapper is the way to go. On unix, If you are launching from a shell sript (at least for bash … Read more
From the Standard: 5.1.2.2.1 Program startup … — argv[argc] shall be a null pointer. So, yes; argv is null terminated
I believe you want the shlex module. >>> import shlex >>> shlex.split(‘-o 1 –long “Some long string”‘) [‘-o’, ‘1’, ‘–long’, ‘Some long string’]
Because you did from os import *, you are (accidenally) using os.open, which indeed requires an integer flag instead of a textual “r” or “w”. Take out that line and you’ll get past that error.
Yes. The non-null pointers in the argv array point to C strings, which are by definition null terminated. The C Language Standard simply states that the array members “shall contain pointers to strings” (C99 §5.1.2.2.1/2). A string is “a contiguous sequence of characters terminated by and including the first null character” (C99 §7.1.1/1), that is, … Read more
The arguments argc and argv of main is used as a way to send arguments to a program, the possibly most familiar way is to use the good ol’ terminal where an user could type cat file. Here the word cat is a program that takes a file and outputs it to standard output (stdout). … Read more
Guesswork (even educated guesswork) is fun but you really need to go to the standards documents to be sure. For example, ISO C11 states (my emphasis): If the value of argc is greater than zero, the string pointed to by argv[0] represents the program name; argv[0][0] shall be the null character if the program name … Read more
If you want to have your arguments C style (array of arguments + number of arguments) you can use $@ and $#. $# gives you the number of arguments. $@ gives you all arguments. You can turn this into an array by args=(“$@”). So for example: args=(“$@”) echo $# arguments passed echo ${args[0]} ${args[1]} ${args[2]} … Read more
argv and argc are how command line arguments are passed to main() in C and C++. argc will be the number of strings pointed to by argv. This will (in practice) be 1 plus the number of arguments, as virtually all implementations will prepend the name of the program to the array. The variables are … Read more