rd235/libstropt

Parse options from a string (supports quotation, option arguments, no malloc needed for parsing)

stropt

Parse options from a string (supports quotation, option arguments, no malloc needed for parsing)

This small library parses a list of options from a string. options can be separated by spaces, commas, semicolons, tabs or new line.

uppercase,bold,underlined

options may have arguments:

ro,noatime,uid=0,gid=0

it is possible to protect symbols and spaces using quote, double quote and backslash.

values='1,2,3,4',equal==

stropt function

int stropt(const char *input, char **tags, char **args, char *buf);

The following function lists the option tags and arguments (without modifying the input string).

#include <stropt.h>
void parse_args(char *input) {
  int tagc = stropt(input, NULL, NULL, 0);
  if(tagc > 0) {
    char buf[strlen(input)+1];
    char *tags[tagc];
    char *args[tagc];
    stropt(input, tags, args, buf);
    for (int i=0; i<tagc; i++)
      printf("%s = %s\n",tags[i], args[i]);
  }
}

it is possible to use the same input string as the buffer for parsing (the original value of the input string gets lost in this way).

#include <stropt.h>
void parse_args(char *input) {
  int tagc = stropt(input, NULL, NULL, 0);
  if(tagc > 0) {
    char *tags[tagc];
    char *args[tagc];
    stropt(input, tags, args, input);
    for (int i=0; i<tagc; i++)
      printf("%s = %s\n",tags[i], args[i]);
  }
}

A typical use case is in combination with strcase:

#include <strcase.h>

void parse_args(char *input) {
  int tagc = stropt(input, NULL, NULL, 0);
  if(tagc > 0) {
    char buf[strlen(input)+1];
    char *tags[tagc];
    char *args[tagc];
    stropt(input, tags, args, buf);
    for (int i=0; i<tagc; i++) {
			switch(strcase(tags[i])) {
				case STRCASE(r,o): global_flags |= READONLY; break;
				case STRCASE(n,o,a,t,i,m,e): global_flags |= NOATIME; break;
				case STRCASE(uid): global_uid = atoi(args[i]); break;
				case STRCASE(gid): global_gid = atoi(args[i]); break;
				default: fprintf(stderr, "Unknown option "%s\n", tags[i]);
			}
		}
  }
}

stroptx function

int stroptx(const char *input, char *features, char *sep, int flags, char **tags, char **args, char *buf);

stroptx is a more flexible and extended interface to stropt: stropt supports several features: single quoting ('), double quoting ("), character escape (\), input on several lines (\n), arguments (=) comment("#")

the string argument named "features" of stroptx allows to enable/disable some of the standard features. when it is NULL, all features are enabled, otherwise each character of features represent a feature to enable. so features == NULL is the same as features == "#=\n'"\". For example to disable comment management feature must be set to "=\n'"\".

the string argument sep of stroptx is the list of separators of tags (the default value is "\t;,").

Flags:

• STROPTX_KEEP_QUOTATION_MARKS_IN_TAGS STROPTX_KEEP_QUOTATION_MARKS_IN_ARGS STROPTX_KEEP_QUOTATION_MARKS usually strops provides the output values without quotation marks (' " ). when the following flags are set the quotation marks are preserved in tags, args or both
• STROPTX_ALLOW_MULTIPLE_SEP when STROPTX_ALLOW_MULTIPLE_SEP is not set multiple separators one after the other appear as one, viceversa when it is set each sequence of two separators means an empty field in between
• STROPTX_NEWLINE_TAGS when STROPTX_NEWLINE_TAGS is set each new line is encoded as a tag "\n"

stropt2str

char *stropt2str(char **tags, char **args, char sep, char eq);

stropt2str rebuilds an option string from the tags/args arrays, sep and eq are the characters to use as separator and assignment marks, repectively. Tags whose value is STROPTX_DELETED_TAG are skipped in the conversion

Install

stropt uses cmake. A standard installation procedure is:

$ mkdir build
$ cd build
$ cmake ..
$ make
$ make install

Use -l stropt as a gcc/ld option to link the library.