popt (3) Linux Manual Page

popt – Parse command line options

Synopsis

#include <popt.h>

poptContext poptGetContext(const char *name, int argc,
                           const char **argv,
                           const struct poptOption *options,
                           int flags);

void poptFreeContext(poptContext con);

void poptResetContext(poptContext con);

int poptGetNextOpt(poptContext con);

const char *poptGetOptArg(poptContext con);

const char *poptGetArg(poptContext con);

const char *poptPeekArg(poptContext con);

const char **poptGetArgs(poptContext con);

const char *const poptStrerror(const int error);

const char *poptBadOption(poptContext con, int flags);

int poptReadDefaultConfig(poptContext con, int flags);

int poptReadConfigFile(poptContext con, char *fn);

int poptAddAlias(poptContext con, struct poptAlias alias,
                 int flags);

int poptParseArgvString(char *s, int *argcPtr,
                        const char ***argvPtr);

int poptDupArgv(int argc, const char **argv, int *argcPtr,
                const char ***argvPtr);

int poptStuffArgs(poptContext con, const char **argv);

Description

The popt library exists essentially for parsing command-line options. It is found superior in many ways when compared to parsing the argv array by hand or using the getopt functions getopt() and getopt_long() [see getopt(3)]. Some specific advantages of popt are: it does not utilize global variables, thus enabling multiple passes in parsing argv ; it can parse an arbitrary array of argv-style elements, allowing parsing of command-line-strings from any source; it provides a standard method of option aliasing (to be discussed at length below.); it can exec external option filters; and, finally, it can automatically generate help and usage messages for the application.

Like getopt_long(), the popt library supports short and long style options. Recall that a short option consists of a – character followed by a single alphanumeric character. A long option, common in GNU utilities, consists of two – characters followed by a string made up of letters, numbers and hyphens. Long options are optionally allowed to begin with a single -, primarily to allow command-line compatibility between popt applications and X toolkit applications. Either type of option may be followed by an argument. A space separates a short option from its arguments; either a space or an = separates a long option from an argument.

The popt library is highly portable and should work on any POSIX platform. The latest version is distributed with rpm and is always available from: ftp://ftp.rpm.org/pub/rpm/dist.

It may be redistributed under the X consortium license, see the file COPYING in the popt source distribution for details.

Basic Popt Usage

1. The Option Table

Applications provide popt with information on their command-line options by means of an "option table," i.e., an array of struct poptOption structures:

#include <popt.h>

struct poptOption {

 const char * longName; /* may be NULL */

 char shortName; /* may be '