cmdline.h (4319B)
1 /* cmdline.h: a reentrant version of getopt(). Written 2006 by Brian 2 * Raiter. This code is in the public domain. 3 */ 4 5 #ifndef _cmdline_h_ 6 #define _cmdline_h_ 7 8 /* The information specifying a single cmdline option. 9 */ 10 typedef struct option { 11 char const *name; /* the option's long name, or "" if none */ 12 char chname; /* a single-char name, or zero if none */ 13 int optval; /* a unique value representing this option */ 14 int arg; /* 0 = no arg, 1 = arg req'd, 2 = optional */ 15 } option; 16 17 /* Parse the given cmdline arguments. list is an array of option 18 * structs, each entry specifying a valid option. The last struct in 19 * the array must have name set to NULL. argc and argv give the 20 * cmdline to parse. callback is the function to call for each option 21 * and non-option found on the cmdline. data is a pointer that is 22 * passed to each invocation of callback. The return value of callback 23 * should be zero to continue processing the cmdline, or any other 24 * value to abort. The return value of readoptions() is the value 25 * returned from the last callback, or zero if no arguments were 26 * found, or -1 if an error occurred. 27 * 28 * When readoptions() encounters a regular cmdline argument (i.e. a 29 * non-option argument), callback() is invoked with opt equal to zero 30 * and val pointing to the argument. When an option is found, 31 * callback() is invoked with opt equal to the optval field in the 32 * option struct corresponding to that option, and val points to the 33 * option's paramter, or is NULL if the option does not take a 34 * parameter. If readoptions() finds an option that does not appear in 35 * the list of valid options, callback() is invoked with opt equal to 36 * '?'. If readoptions() encounters an option that is missing its 37 * required parameter, callback() is invoked with opt equal to ':'. If 38 * readoptions() finds a parameter on a long option that does not 39 * admit a parameter, callback() is invoked with opt equal to '='. In 40 * each of these cases, val will point to the erroneous option 41 * argument. 42 */ 43 extern int readoptions(option const* list, int argc, char **argv, 44 int (*callback)(int opt, char const *val, void *data), 45 void *data); 46 47 /* Parse the given file. list is an array of option structs, in the 48 * same form as taken by readoptions(). fp is a pointer to an open 49 * text file. callback is the function to call for each line found in 50 * the configuration file. data is a pointer that is passed to each 51 * invocation of callback. The return value of readcfgfile() is the 52 * value returned from the last callback, or zero if no arguments were 53 * found, or -1 if an error occurred while reading the file. 54 * 55 * The function will ignore lines that contain only whitespace, or 56 * lines that begin with a hash sign. All other lines should be of the 57 * form "OPTION=VALUE", where OPTION is one of the long options in 58 * list. Whitespace around the equal sign is permitted. An option that 59 * takes no arguments can either have a VALUE of 0 or 1, or omit the 60 * "=VALUE" entirely. (A VALUE of 0 will behave the same as if the 61 * line was not present.) 62 */ 63 extern int readcfgfile(option const* list, FILE *fp, 64 int (*callback)(int opt, char const *val, void *data), 65 void *data); 66 67 68 /* Create an argc-argv pair from a string containing a command line. 69 * cmdline is the string to be parsed. argcp points to the variable to 70 * receive the argc value, and argvp points to the variable to receive 71 * the argv value. argvp can be NULL if the caller just wants to get 72 * argc. Zero is returned on failure. This function allocates memory 73 * on behalf of the caller. The memory is allocated as a single block, 74 * so it is sufficient to simply free() the pointer returned through 75 * argvp. Note that argv[0] will always be initialized to NULL; the 76 * first argument will be stored in argv[1]. The string is parsed by 77 * separating arguments on whitespace boundaries. Space within 78 * substrings enclosed in single-quotes is ignored. A substring 79 * enclosed in double-quotes is treated the same, except that the 80 * backslash is recognized as an escape character within such a 81 * substring. Enclosing quotes and escaping backslashes are not copied 82 * into the argv values. 83 */ 84 extern int makecmdline(char const *cmdline, int *argcp, char ***argvp); 85 86 #endif