/* cmdline.h: a reentrant version of getopt(). Written 2006 by Brian
* Raiter. This code is in the public domain.
*/
#ifndef _cmdline_h_
#define _cmdline_h_
/* The information specifying a single cmdline option.
*/
typedef struct option {
char const *name; /* the option's long name, or "" if none */
char chname; /* a single-char name, or zero if none */
int optval; /* a unique value representing this option */
int arg; /* 0 = no arg, 1 = arg req'd, 2 = optional */
} option;
/* Parse the given cmdline arguments. list is an array of option
* structs, each entry specifying a valid option. The last struct in
* the array must have name set to NULL. argc and argv give the
* cmdline to parse. callback is the function to call for each option
* and non-option found on the cmdline. data is a pointer that is
* passed to each invocation of callback. The return value of callback
* should be zero to continue processing the cmdline, or any other
* value to abort. The return value of readoptions() is the value
* returned from the last callback, or zero if no arguments were
* found, or -1 if an error occurred.
*
* When readoptions() encounters a regular cmdline argument (i.e. a
* non-option argument), callback() is invoked with opt equal to zero
* and val pointing to the argument. When an option is found,
* callback() is invoked with opt equal to the optval field in the
* option struct corresponding to that option, and val points to the
* option's paramter, or is NULL if the option does not take a
* parameter. If readoptions() finds an option that does not appear in
* the list of valid options, callback() is invoked with opt equal to
* '?'. If readoptions() encounters an option that is missing its
* required parameter, callback() is invoked with opt equal to ':'. If
* readoptions() finds a parameter on a long option that does not
* admit a parameter, callback() is invoked with opt equal to '='. In
* each of these cases, val will point to the erroneous option
* argument.
*/
extern int readoptions(option const* list, int argc, char **argv,
int (*callback)(int opt, char const *val, void *data),
void *data);
/* Parse the given file. list is an array of option structs, in the
* same form as taken by readoptions(). fp is a pointer to an open
* text file. callback is the function to call for each line found in
* the configuration file. data is a pointer that is passed to each
* invocation of callback. The return value of readcfgfile() is the
* value returned from the last callback, or zero if no arguments were
* found, or -1 if an error occurred while reading the file.
*
* The function will ignore lines that contain only whitespace, or
* lines that begin with a hash sign. All other lines should be of the
* form "OPTION=VALUE", where OPTION is one of the long options in
* list. Whitespace around the equal sign is permitted. An option that
* takes no arguments can either have a VALUE of 0 or 1, or omit the
* "=VALUE" entirely. (A VALUE of 0 will behave the same as if the
* line was not present.)
*/
extern int readcfgfile(option const* list, FILE *fp,
int (*callback)(int opt, char const *val, void *data),
void *data);
/* Create an argc-argv pair from a string containing a command line.
* cmdline is the string to be parsed. argcp points to the variable to
* receive the argc value, and argvp points to the variable to receive
* the argv value. argvp can be NULL if the caller just wants to get
* argc. Zero is returned on failure. This function allocates memory
* on behalf of the caller. The memory is allocated as a single block,
* so it is sufficient to simply free() the pointer returned through
* argvp. Note that argv[0] will always be initialized to NULL; the
* first argument will be stored in argv[1]. The string is parsed by
* separating arguments on whitespace boundaries. Space within
* substrings enclosed in single-quotes is ignored. A substring
* enclosed in double-quotes is treated the same, except that the
* backslash is recognized as an escape character within such a
* substring. Enclosing quotes and escaping backslashes are not copied
* into the argv values.
*/
extern int makecmdline(char const *cmdline, int *argcp, char ***argvp);
#endif
