--- name: "stropt" section: "3" platform: "linux" package: "libstropt-dev" version: "0.1.2-1" release: "Debian 13 (Trixie)" platforms: ["linux", "macos"] url: "https://new.carta.tech/stropt" --- # stropt(3) Parse options from a string (it supports quotation, option arguments) ## NAME stropt, stroptx, stropt2buf, stropt2str - Parse options from a string (it supports quotation, option arguments) ## SYNOPSIS **#include \** **int stropt(const char \****input***, char \*\****tags***, char \*\****args***, char \****buf***);** **int stroptx(const char \****input***, char \****features***, char \****sep***, int** *flags***, char \*\****tags***, char \*\****args***, char \****buf***);** **char \*stropt2buf(void \****buf***, size\_t** *size***, char \*\****tags***, char \*\****args***, char** *sep***, char** *eq***);** **char \*stropt2str(char \*\****tags***, char \*\****args***, char** *sep***, char** *eq***);** ## DESCRIPTION This small library parses a list of options from a string. Options can be separated by spaces, commas, semicolons, tabs or new line. (e.g. *uppercase,bold,underlined* ). Options may have arguments (e.g. *ro,noatime,uid=0,gid=0* ). It is possible to protect symbols and spaces using quote, double quote and backslash (e.g. *values='1,2,3,4',equal==* ) - **stropt** This function parses a list of options from the string *input*. Options can be separated by commas, semicolons, tabs oe new lines. Options may have arguments in the form *keyword=value*. *buf* is a temporary buffer, it must have the same size of the *input* string (including the NULL terminator). *tags* and *args* are the resulting arrays of options and arguments respectively. Both *tags* and *args* have one NULL terminator element at the end. When an option has not an argument the corresponding *args* element is NULL. For example if *input* is "font=12,typeface=bodoni,italic", *tags\[0\]*="font", *tags\[1\]*="typeface", *tags\[2\]*="italic", *tags\[4\]*=NULL, *args\[0\]*="12", *args\[1\]*="bodoni", *args\[0\]*=NULL, *args\[4\]*=NULL. - When **stropt** is called with *tags*, *args*, and *buf* all NULL, it parses the input, counting the options. The return value can be used to allocate suitable arrays for *tags* and *args*. - It is possible to use the same variable as *input* and *buffer*. In this case the original value of *input* is overwritten. - **stroptx** This is a more configurable extension of **stropt**. Arguments having the same names as in **stropt** have the same meaning as explained above. - The string *features* permits one to enable/disable some of the standard features. Each feature corresponds to a mnemonic character, when the character is in the *features* string the feature is enabled: - **'**: single quoting, - **"**: double quoting, - **\\**: character escape, - **\\n**:input in several lines, - **=**: allow arguments, - **#**: support comments. - If *features* is NULL all the features are enabled, when *features* is an empty string all features are disabled. - All the characters included in *sep* are considered as option separators. If *sep* is NULL, the default value is " \\t;,". - The *flag* argument may include the bitwise OR of any of the following flag values: - **STROPTX\_KEEP\_QUOTATION\_MARKS\_IN\_TAGS**: preserve the quotation marks in tags, - **STROPTX\_KEEP\_QUOTATION\_MARKS\_IN\_ARGS**: preserve the quotation marks in args, - **STROPTX\_KEEP\_QUOTATION\_MARKS**: shortcut for **STROPTX\_KEEP\_QUOTATION\_MARKS\_IN\_TAGS \| STROPTX\_KEEP\_QUOTATION\_MARKS\_IN\_ARGS** - **STROPTX\_ALLOW\_MULTIPLE\_SEP**: when it is not set, a sequence of separators is processed as a single separator, when it is set each sequence of two separators means an empty field in between. - **STROPTX\_NEWLINE\_TAGS**: when set each new line is encoded as a tag "\\n". - **stropt2buf** This function re-encodes an array of options (and an array of arguments) in a string. It is the inverse function of of **stropt**. Given a buffer *buf* of size *size*, the array of options *tags* with their corresponding values in the array *args* is encoded using the separator character *sep* and the assignment character *eq*. - Elements whose option tag (element of *tags*) value is **STROPTX\_DELETED\_TAG** are omitted in output. - **stropt2str** This is the sibling function of **stropt2buf**. It uses dynamically allocated memory instead of a buffer provided by the caller. The resulting string must be deallocated using [free(3)](/free/3.md). ## RETURN VALUE - • **stropt** and **stroptx** return the number of options + 1. - • **stropt2buf** and **stropt2str** return the resulting string. - ## EXAMPLES The following function lists the option tags and arguments (without modyfying the input string). - ``` void parse_args(char *input) { int tagc = stropt(input, NULL, NULL, NULL); if(tagc > 0) { char buf[strlen(input)+1]; char *tags[tagc]; char *args[tagc]; stropt(input, tags, args, buf); for (int i=0; i 0) { char *tags[tagc]; char *args[tagc]; stropt(input, tags, args, input); for (int i=0; i 0) { char buf[strlen(input)+1]; char *tags[tagc]; stropt(input, tags, NULL, buf); for (int i=0; i #include #include #include #include char *delete_uppercase_options(const char *input) { int tagc = stroptx(input, "", ",",STROPTX_ALLOW_MULTIPLE_SEP, NULL, NULL, NULL); if(tagc > 0) { char buf[strlen(input)+1]; char *tags[tagc]; int i; stroptx(input, "", ",",STROPTX_ALLOW_MULTIPLE_SEP, tags, NULL, buf); for (i = 0; i < tagc; i++) if (tags[i] && isupper(tags[i][0])) tags[i] = STROPTX_DELETED_TAG; return stropt2str(tags, NULL, ',', '='); } else return NULL; } int main(int argc, char *argv[]) { if (argc > 1) { char *result = delete_uppercase_options(argv[1]); printf("%s\n", result); free(result); } return 0; } ``` - ## AUTHOR VirtualSquare. Project leader: Renzo Davoli.