--- /dev/null
+#ifndef _XSTRING_H
+#define _XSTRING_H 1
+
+#include <assert.h>
+#include <sys/types.h>
+
+/**
+ * struct xstring - string metadata
+ * @str: pointer to buf
+ * @len: current length of buf contents
+ * @cap: maximum capacity of buf
+ * @truncated: -1 indicates truncation
+ */
+typedef struct xstring {
+ char *str;
+ size_t len;
+ size_t cap;
+ int truncated;
+} xstring;
+
+/**
+ * xstrNew - mallocs and inits
+ * @size: size of buffer to allocate
+ *
+ * mallocs both buffer and struct, calls xstrInit
+ *
+ * Return: ptr to xstring or NULL
+ */
+xstring *xstrNew(const size_t size);
+
+/**
+ * xstrInit - initialize an xstring struct
+ * @x: pointer to xstring
+ * @str: buffer to manage
+ * @size: size of str
+ * @keep: if !0, keep existing contents of str;
+ * otherwise, str[0] = '\0'
+ *
+ * Return: x->truncated
+ */
+int xstrInit(xstring *x, char *str, const size_t size, int keep);
+
+/**
+ * xstrClear - clear xstring
+ * @x: pointer to xstring
+ *
+ * This sets x->len and x->truncated to 0 and str[0] to '\0';
+ *
+ * Return: x->truncated (always 0)
+ */
+#define xstrClear(x) (xstrInit((x), (x)->str, (x)->cap, 0))
+
+/**
+ * xstrAddChar - add a single character
+ * @x: pointer to xstring
+ * @c: character to append
+ *
+ * Return: x->truncated
+ */
+int xstrAddChar(xstring *x, const char c);
+
+/**
+ * xstrAdd - append a string
+ * @x: pointer to xstring
+ * @src: string to append
+ *
+ * Append as much from src as fits - if not all, flag truncation.
+ *
+ * Return: x->truncated
+ */
+int xstrAdd(xstring *x, const char *src);
+
+/**
+ * xstrAddSub - append a substring
+ * @x: pointer to xstring
+ * @src: string to append
+ * @len: length of substring
+ *
+ * Append substring and '\0' if len fits, otherwise flag truncation.
+ *
+ * Return: x->truncated
+ */
+int xstrAddSub(xstring *x, const char *src, size_t len);
+
+/** xstrCat - append multiple strings
+ * @x: pointer to xstring
+ * @...: one or more strings followed by NULL
+ *
+ * Run xstrAdd for each string.
+ *
+ * Return: x->truncated
+ */
+int xstrCat(xstring *x, ...);
+
+/** xstrJoin - append multiple strings joined by sep
+ * @x: pointer to xstring
+ * @sep: separator string
+ * @...: one or more strings followed by NULL
+ *
+ * Run xstrAdd for each string and append sep between each pair.
+ *
+ * Return: x->truncated
+ */
+int xstrJoin(xstring *x, const char *sep, ...);
+
+/**
+ * xstrAddSubs - append multiple substrings
+ * @x: pointer to xstring
+ * @...: one or more pairs of string and length followed by NULL
+ *
+ * Run xstrAddSub for each pair of string and length.
+ *
+ * Return: x->truncated
+ */
+int xstrAddSubs(xstring *x, ...);
+
+#define transact(x, y) ({ \
+ size_t last; \
+ int ret; \
+ assert((x)); \
+ last = (x)->len; \
+ if ((ret = (y)) == -1) { \
+ (x)->len = last; \
+ *((x)->str + (x)->len) = '\0'; \
+ } \
+ ret; \
+})
+
+/**
+ * xstrAddT - append a string as a transaction
+ * @x: pointer to xstring
+ * @src: string to append
+ *
+ * Run xstrAdd. Reterminate at inital length if truncation occurs.
+ *
+ * Return: x->truncated
+ */
+#define xstrAddT(x, y) transact(x, xstrAdd((x), y))
+
+/** xstrCatT - append multiple strings as one transaction
+ * @x: pointer to xstring
+ * @...: one or more strings followed by NULL
+ *
+ * Run xstrCat. Reterminate at inital length if truncation occurs.
+ *
+ * Return: x->truncated
+ */
+#define xstrCatT(x, y...) transact(x, xstrCat((x) , ## y))
+
+/** xstrJoinT - append multiple strings joined by sep as one transaction
+ * @x: pointer to xstring
+ * @sep: separator string
+ * @...: one or more strings followed by NULL
+ *
+ * Run xstrJoin. Reterminate at inital length if truncation occurs.
+ *
+ * Return: x->truncated
+ */
+#define xstrJoinT(x, y...) transact(x, xstrJoin((x) , ## y))
+
+/**
+ * xstrAddSubsT - append multiple substrings as one transaction
+ * @x: pointer to xstring
+ * @...: one or more pairs of string and length followed by NULL
+ *
+ * Run xstrAddSubs. Reterminate at inital length if truncation occurs.
+ *
+ * Return: x->truncated
+ */
+#define xstrAddSubsT(x, y...) transact(x, xstrAddSubs((x) , ## y))
+
+/**
+ * xstrAddSubT - same as xstrAddSub
+ */
+// addsub is already transactional
+#define xstrAddSubT xstrAddSub
+
+#define unknown -1
+
+/**
+ * xstrEq3 - test if two strings are equal
+ * @x: pointer to xstring
+ * @y: pointer to xstring
+ *
+ * Return true (1) if the strings held by x and y match and no truncation has occurred.
+ * Return unknown (-1) if either is flagged as truncated.
+ * Return false (0) otherwise.
+ *
+ * Return: -1, 0, or 1
+ */
+int xstrEq3(xstring *x, xstring *y);
+
+/**
+ * xstrEq - test if two strings are equal
+ * @x: pointer to xstring
+ * @y: pointer to xstring
+ *
+ * Same as xstrEq3, but return false (0) for unknown (-1).
+ *
+ * Return: 0 or 1
+ */
+#define xstrEq(x, y) (xstrEq3((x), (y)) == 1)
+
+/**
+ * xstrContains3 - test if first string contains second
+ * @x: pointer to xstring
+ * @y: pointer to xstring
+ * @where: -1 (ends), 0 (anywhere), 1 (begins)
+ *
+ * If neither x nor y are truncated, returns true (1) or false (0).
+ * If y is truncated, return unknown (-1).
+ * If x is truncated, return true (1) if known portion of x contains y, unknown (-1) otherwise.
+ *
+ * Return: -1, 0, or 1
+ */
+int xstrContains3(xstring *x, xstring *y, int where);
+
+/**
+ * xstrContains3 - test if first string contains second
+ * @x: pointer to xstring
+ * @y: pointer to xstring
+ * @where: -1 (ends), 0 (anywhere), 1 (begins)
+ *
+ * Same as xstrContains3, but return false (0) for unknown (-1).
+ *
+ * Return: 0 or 1
+ */
+#define xstrContains(x, y, w) (xstrContains3((x), (y), (w)) == 1)
+
+/**
+ * xstrFree - free malloced memory
+ * @x: pointer to xstring
+ */
+void xstrFree(xstring *x);
+
+#endif
projects / ccan / blobdiff