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diff --git a/src/modules/systemlib/uthash/doc/utstring.txt b/src/modules/systemlib/uthash/doc/utstring.txt new file mode 100644 index 000000000..abfdcd107 --- /dev/null +++ b/src/modules/systemlib/uthash/doc/utstring.txt @@ -0,0 +1,178 @@ +utstring: dynamic string macros for C +===================================== +Troy D. Hanson <thanson@users.sourceforge.net> +v1.9.5, November 2011 + +include::sflogo.txt[] +include::topnav_utstring.txt[] + +Introduction +------------ +include::toc.txt[] + +A set of very basic dynamic string macros for C programs are included with +uthash in `utstring.h`. To use these macros in your own C program, just +copy `utstring.h` into your source directory and use it in your programs. + + #include "utstring.h" + +The dynamic string supports basic operations such as inserting data (including +binary data-- despite its name, utstring is not limited to string content), +concatenation, getting the length and content, and clearing it. The string +<<operations,operations>> are listed below. + +Download +~~~~~~~~ +To download the `utstring.h` header file, follow the link on the +http://uthash.sourceforge.net[uthash home page]. + +BSD licensed +~~~~~~~~~~~~ +This software is made available under the +link:license.html[revised BSD license]. +It is free and open source. + +Platforms +~~~~~~~~~ +The 'utstring' macros have been tested on: + + * Linux, + * Windows, using Visual Studio 2008 and Visual Studio 2010 + +Usage +----- + +Declaration +~~~~~~~~~~~ + +The dynamic string itself has the data type `UT_string`. It is declared like, + + UT_string *str; + +New and free +~~~~~~~~~~~~ +The next step is to create the string using `utstring_new`. Later when you're +done with it, `utstring_free` will free it and all its content. + +Manipulation +~~~~~~~~~~~~ +The `utstring_printf` or `utstring_bincpy` operations insert (copy) data into +the string. To concatenate one utstring to another, use `utstring_concat`. To +clear the content of the string, use `utstring_clear`. The length of the string +is available from `utstring_len`, and its content from `utstring_body`. This +evaluates to a `char*`. The buffer it points to is always null-terminated. +So, it can be used directly with external functions that expect a string. +This automatic null terminator is not counted in the length of the string. + +Samples +~~~~~~~ + +These examples show how to use utstring. + +.Sample 1 +------------------------------------------------------------------------------- +#include <stdio.h> +#include "utstring.h" + +int main() { + UT_string *s; + + utstring_new(s); + utstring_printf(s, "hello world!" ); + printf("%s\n", utstring_body(s)); + + utstring_free(s); + return 0; +} +------------------------------------------------------------------------------- + +The next example is meant to demonstrate that printf 'appends' to the string. +It also shows concatenation. + +.Sample 2 +------------------------------------------------------------------------------- +#include <stdio.h> +#include "utstring.h" + +int main() { + UT_string *s, *t; + + utstring_new(s); + utstring_new(t); + + utstring_printf(s, "hello " ); + utstring_printf(s, "world " ); + + utstring_printf(t, "hi " ); + utstring_printf(t, "there " ); + + utstring_concat(s, t); + printf("length: %u\n", utstring_len(s)); + printf("%s\n", utstring_body(s)); + + utstring_free(s); + utstring_free(t); + return 0; +} +------------------------------------------------------------------------------- + +The last example shows how binary data can be inserted into the string. It also +clears the string and prints new data into it. + +.Sample 3 +------------------------------------------------------------------------------- +#include <stdio.h> +#include "utstring.h" + +int main() { + UT_string *s; + char binary[] = "\xff\xff"; + + utstring_new(s); + utstring_bincpy(s, binary, sizeof(binary)); + printf("length is %u\n", utstring_len(s)); + + utstring_clear(s); + utstring_printf(s,"number %d", 10); + printf("%s\n", utstring_body(s)); + + utstring_free(s); + return 0; +} +------------------------------------------------------------------------------- + +[[operations]] +Reference +--------- +These are the utstring operations. + +Operations +~~~~~~~~~~ + +[width="100%",cols="50<m,40<",grid="none",options="none"] +|=============================================================================== +| utstring_new(s) | allocate a new utstring +| utstring_renew(s) | allocate a new utstring (if s is `NULL`) otherwise clears it +| utstring_free(s) | free an allocated utstring +| utstring_init(s) | init a utstring (non-alloc) +| utstring_done(s) | dispose of a utstring (non-allocd) +| utstring_printf(s,fmt,...) | printf into a utstring (appends) +| utstring_bincpy(s,bin,len) | insert binary data of length len (appends) +| utstring_concat(dst,src) | concatenate src utstring to end of dst utstring +| utstring_clear(s) | clear the content of s (setting its length to 0) +| utstring_len(s) | obtain the length of s as an unsigned integer +| utstring_body(s) | get `char*` to body of s (buffer is always null-terminated) +|=============================================================================== + +Notes +~~~~~ + +1. `utstring_new` and `utstring_free` are used to allocate a new string and free it, + while `utstring_init` and `utstring_done` can be used if the UT_string is already + allocated and just needs to be initialized or have its internal resources + freed. +2. `utstring_printf` is actually a function defined statically in `utstring.h` + rather than a macro. + +// vim: set nowrap syntax=asciidoc: + |