Processargv

Processargv refers to the argument vector of a running process, the sequence of strings provided to a program at startup that convey the program name, options, and user input. The exact representation and access method differ by language and environment, but the general idea is to expose startup arguments to the program so it can configure its behavior without hard-coded values.

In many compiled languages, the entry point receives argc and argv. For example, in C and C++, main(int argc, char *argv[]) uses argc as the argument count and argv as an array of strings, with argv[0] typically the executable path. In Java, command-line arguments are received as the String[] args parameter to the main method. In Python, the list sys.argv provides similar functionality, with the first element usually the script name. In JavaScript runtimes like Node.js, the global process.argv array contains the node executable path, the script path, and any subsequent user-supplied arguments.

Parsing processargv is a common task to interpret options (flags), key-value pairs, and positional arguments. Languages offer specialized libraries to help, such as getopt or clap in various ecosystems, argparse in Python, yargs in Node.js, or Apache Commons CLI in Java. Robust parsers handle quoting, escaping, and the distinction between options and positional input, and they validate arguments to prevent invalid configurations or security issues.

Common pitfalls include assuming fixed positions for options, failing to handle missing values, or neglecting platform-specific differences in quoting and path formats. Because processargv originates from user input, programs should validate and sanitize arguments before use and provide helpful error messages when inputs are invalid.

See also: command-line interfaces, argument parsing, getopt, argparse, yargs.