/*----- Handy macros ------------------------------------------------------*/
#define N(v) (sizeof(v)/sizeof((v)[0]))
+ /* The number of elements in the array V. */
+/* Figure out the compiler version to see whether fancy tricks will work. */
#if defined(__GNUC__)
# define GCC_VERSION_P(maj, min) \
(__GNUC__ > (maj) || (__GNUC__ == (maj) && __GNUC_MINOR__ >= (min)))
#endif
#if GCC_VERSION_P(2, 5) || CLANG_VERSION_P(3, 3)
+
# define NORETURN __attribute__((__noreturn__))
+ /* Mark a function as not returning. */
+
# define PRINTF_LIKE(fix, aix) __attribute__((__format__(printf, fix, aix)))
+ /* Mark a function as accepting a printf(3)-like format string as
+ * argument FIX, with arguments to be substituted starting at AIX.
+ */
#endif
#if GCC_VERSION_P(4, 0) || CLANG_VERSION_P(3, 3)
+
# define EXECL_LIKE(ntrail) __attribute__((__sentinel__(ntrail)))
+ /* Mark a function as expecting a variable number of arguments
+ * terminated by a null pointer, followed by NTRAIL further
+ * arguments.
+ */
+
#endif
+/* Couldn't detect fancy compiler features. We'll have to make do
+ * without.
+ */
+#ifndef NORETURN
+# define NORETURN
+#endif
+#ifndef PRINTF_LIKE
+# define PRINTF_LIKE(fix, aix)
+#endif
+#ifndef EXECL_LIKE
+# define EXECL_LIKE(ntrail)
+#endif
+
+#define DISCARD(x) do if (x); while (0)
+ /* Discard the result of evaluating expression X, without upsetting
+ * the compiler.
+ */
+
+#define END ((const char *)0)
+ /* A null pointer to terminate the argument tail to an `EXECL_LIKE'
+ * function. (Note that `NULL' is /not/ adequate for this purpose,
+ * since it might expand simply to `0', which is an integer, not a
+ * pointer, and might well be the wrong size and/or value.)
+ */
+
+/* Wrap up <ctype.h> macros with explicit conversions to `unsigned char'. */
#define CTYPE_HACK(func, ch) (func((unsigned char)(ch)))
#define ISSPACE(ch) CTYPE_HACK(isspace, ch)
#define ISALNUM(ch) CTYPE_HACK(isalnum, ch)
+#define ISXDIGIT(ch) CTYPE_HACK(isxdigit, ch)
+#define TOLOWER(ch) CTYPE_HACK(tolower, ch)
+#define TOUPPER(ch) CTYPE_HACK(toupper, ch)
+/* Wrap up comparison functions to take an ordering relation as part of their
+ * syntax. This makes it much harder to screw up.
+ */
#define MEMCMP(x, op, y, n) (memcmp((x), (y), (n)) op 0)
#define STRCMP(x, op, y) (strcmp((x), (y)) op 0)
#define STRNCMP(x, op, y, n) (strncmp((x), (y), (n)) op 0)
-#define DISCARD(x) do if (x); while (0)
-
-#define END ((const char *)0)
-
#ifndef SIZE_MAX
# define SIZE_MAX (-(size_t)1)
#endif
-
-/*----- Miscellany --------------------------------------------------------*/
-
-extern int str_lt(const char */*a*/, size_t /*an*/,
- const char */*b*/, size_t /*bn*/);
+ /* The largest value that can be stored in an object of type
+ * `size_t'. A proper <limits.h> setting would be a preprocessor-
+ * time constant, but we don't actually need that.
+ */
/*----- Diagnostic utilities ----------------------------------------------*/
extern const char *progname;
+ /* Our program name, for use in error messages. */
extern void set_progname(const char */*prog*/);
+ /* Set `progname' from the pathname in PROG (typically from
+ * `argv[0]').
+ */
+
extern void vmoan(const char */*msg*/, va_list /*ap*/);
+ /* Report an error or warning in Unix style, given a captured
+ * argument cursor.
+ */
+
extern PRINTF_LIKE(1, 2) void moan(const char */*msg*/, ...);
+ /* Issue a warning message. */
+
extern NORETURN PRINTF_LIKE(1, 2) void lose(const char */*msg*/, ...);
+ /* Issue a fatal error message and exit unsuccessfully. */
/*----- Memory allocation -------------------------------------------------*/
extern void *xmalloc(size_t /*n*/);
+ /* Allocate and return a pointer to N bytes, or report a fatal error.
+ *
+ * Release the pointer using `free' as usual. If N is zero, returns
+ * null (but you are not expected to check for this).
+ */
+
extern void *xrealloc(void */*p*/, size_t /*n*/);
+ /* Resize the block at P (from `malloc' or `xmalloc') to be N bytes
+ * long.
+ *
+ * The block might (and probably will) move, so it returns the new
+ * address. If N is zero, then the block is freed (if necessary) and
+ * a null pointer returned; otherwise, if P is null then a fresh
+ * block is allocated. If allocation fails, then a fatal error is
+ * reported.
+ */
+
extern char *xstrndup(const char */*p*/, size_t /*n*/);
+ /* Allocate and return a copy of the N-byte string starting at P.
+ *
+ * The new string is null-terminated, though P need not be. If
+ * allocation fails, then a fatal error is reported.
+ */
+
extern char *xstrdup(const char */*p*/);
+ /* Allocate and return a copy of the null-terminated string starting
+ * at P.
+ *
+ * If allocation fails, then a fatal error is reported.
+ */
/*----- Dynamic strings ---------------------------------------------------*/
+/* A dynamic string.
+ *
+ * Note that the string might not be null-terminated.
+ */
struct dstr {
- char *p;
- size_t len, sz;
+ char *p; /* string base address */
+ size_t len; /* current string length */
+ size_t sz; /* allocated size of buffer */
};
#define DSTR_INIT { 0, 0, 0 }
extern void dstr_init(struct dstr */*d*/);
+ /* Initialize the string D.
+ *
+ * Usually you'd use the static initializer `DSTR_INIT'.
+ */
+
extern void dstr_reset(struct dstr */*d*/);
+ /* Reset string D so it's empty again. */
+
extern void dstr_ensure(struct dstr */*d*/, size_t /*n*/);
+ /* Ensure that D has at least N unused bytes available. */
+
extern void dstr_release(struct dstr */*d*/);
+ /* Release the memory held by D.
+ *
+ * It must be reinitialized (e.g., by `dstr_init') before it can be
+ * used again.
+ */
+
extern void dstr_putm(struct dstr */*d*/, const void */*p*/, size_t /*n*/);
+ /* Append the N-byte string at P to D.
+ *
+ * P need not be null-terminated. D will not be null-terminated
+ * afterwards.
+ */
+
extern void dstr_puts(struct dstr */*d*/, const char */*p*/);
+ /* Append the null-terminated string P to D.
+ *
+ * D /is/ guaranteed to be null-terminated after this.
+ */
+
extern void dstr_putc(struct dstr */*d*/, int /*ch*/);
+ /* Append the single character CH to D.
+ *
+ * D will not be null-terminated afterwards.
+ */
+
+extern void dstr_putcn(struct dstr */*d*/, int /*ch*/, size_t /*n*/);
+ /* Append N copies of the character CH to D.
+ *
+ * D will not be null-terminated afterwards.
+ */
+
extern void dstr_putz(struct dstr */*d*/);
+ /* Null-terminate the string D.
+ *
+ * This doesn't change the length of D. If further stuff is appended
+ * then the null terminator will be overwritten.
+ */
+
extern void dstr_vputf(struct dstr */*d*/,
const char */*p*/, va_list /*ap*/);
+ /* Append stuff to D, determined by printf(3) format string P and
+ * argument tail AP.
+ *
+ * D will not be null-terminated afterwards.
+ */
+
extern PRINTF_LIKE(2, 3)
void dstr_putf(struct dstr */*d*/, const char */*p*/, ...);
+ /* Append stuff to D, determined by printf(3) format string P and
+ * arguments.
+ *
+ * D will not be null-terminated afterwards.
+ */
+
extern int dstr_readline(struct dstr */*d*/, FILE */*fp*/);
+ /* Append the next input line from FP to D.
+ *
+ * Return 0 on success, or -1 if reading immediately fails or
+ * encounters end-of-file (call ferror(3) to distinguish). Any
+ * trailing newline is discarded: it is not possible to determine
+ * whether the last line was ended with a newline. D is guaranteed
+ * to be null-terminated afterwards.
+ */
/*----- Dynamic vectors of strings ----------------------------------------*/
+/* A dynamic vector of strings.
+ *
+ * This machinery only actually tracks character pointers. It assumes that
+ * the caller will manage the underlying storage for the strings.
+ *
+ * Note that `v' always points to the first element in the vector. The
+ * underlying storage starts `o' slots before this.
+*/
struct argv {
- const char **v;
- size_t o, n, sz;
+ char **v; /* pointer the first element */
+ size_t n; /* length of the vector */
+ size_t o; /* number of spare slots at start */
+ size_t sz; /* allocated size (in slots) */
};
#define ARGV_INIT { 0, 0, 0, 0 }
extern void argv_init(struct argv */*a*/v);
+ /* Initialize the vector AV.
+ *
+ * Usually you'd use the static initializer `ARGV_INIT'.
+ */
+
extern void argv_reset(struct argv */*av*/);
+ /* Reset the vector AV so that it's empty again. */
+
extern void argv_ensure(struct argv */*av*/, size_t /*n*/);
+ /* Ensure that AV has at least N unused slots at the end. */
+
extern void argv_ensure_offset(struct argv */*av*/, size_t /*n*/);
+ /* Ensure that AV has at least N unused slots at the /start/. */
+
extern void argv_release(struct argv */*av*/);
-extern void argv_append(struct argv */*av*/, const char */*p*/);
+ /* Release the memory held by AV.
+ *
+ * It must be reinitialized (e.g., by `argv_init') before it can be
+ * used again.
+ */
+
+extern void argv_append(struct argv */*av*/, char */*p*/);
+ /* Append the pointer P to AV. */
+
extern void argv_appendz(struct argv */*av*/);
+ /* Append a null pointer to AV, without extending the vactor length.
+ *
+ * The null pointer will be overwritten when the next string is
+ * appended.
+ */
+
extern void argv_appendn(struct argv */*av*/,
- const char *const */*v*/, size_t /*n*/);
+ char *const */*v*/, size_t /*n*/);
+ /* Append a N-element vector V of pointers to AV. */
+
extern void argv_appendav(struct argv */*av*/, const struct argv */*bv*/);
+ /* Append the variable-length vector BV to AV. */
+
extern void argv_appendv(struct argv */*av*/, va_list /*ap*/);
+ /* Append the pointers from a variable-length argument list AP to AV.
+ *
+ * The list is terminated by a null pointer.
+ */
+
extern EXECL_LIKE(0) void argv_appendl(struct argv */*av*/, ...);
-extern void argv_prepend(struct argv */*av*/, const char */*p*/);
+ /* Append the argument pointers, terminated by a null pointer, to
+ * AV.
+ */
+
+extern void argv_prepend(struct argv */*av*/, char */*p*/);
+ /* Prepend the pointer P to AV. */
+
extern void argv_prependn(struct argv */*av*/,
- const char *const */*v*/, size_t /*n*/);
+ char *const */*v*/, size_t /*n*/);
+ /* Prepend a N-element vector V of pointers to AV. */
+
extern void argv_prependav(struct argv */*av*/, const struct argv */*bv*/);
+ /* Prepend the variable-length vector BV to AV. */
+
extern void argv_prependv(struct argv */*av*/, va_list /*ap*/);
+ /* Prepend the pointers from a variable-length argument list AP to
+ * AV.
+ *
+ * The list is terminated by a null pointer.
+ */
+
extern EXECL_LIKE(0) void argv_prependl(struct argv */*av*/, ...);
+ /* Prepend the argument pointers, terminated by a null pointer, to
+ * AV.
+ */
/*----- Treaps ------------------------------------------------------------*/
+/* A `treap' is a data structure for associating values with keys. This
+ * implementation assumes that keys are simply text strings.
+ */
struct treap {
struct treap_node *root;
};
#define TREAP_INIT { 0 }
+/* A treap is a combination of a binary search tree and a binary heap. The
+ * nodes are ordered according to the search keys, in the usual way, so that
+ * all the keys in a node's left subtree precede that node's key, and all of
+ * the keys in its right subtree follow the node's key. The trick is that
+ * the tree must /also/ satisfy the heap condition regarding randomly
+ * assigned `weights' attached to each node: so a node's weight must not be
+ * less than their weight of either of its children.
+ *
+ * This combination uniquely determines the structure of the tree, except for
+ * nodes whose weights exactly match one (or both) of their children. (The
+ * root must be the heaviest node in the tree. The root's key splits the
+ * remaining nodes into left and right subtrees, whose structure is then
+ * uniquely determined by induction.)
+ *
+ * This is an /intrusive/ data structure. A caller is expected to include a
+ * `struct treap_node' as (probably) the initial part of a larger structure.
+ */
struct treap_node {
- unsigned wt;
- struct treap_node *left, *right;
- char *k; size_t kn;
+ unsigned wt; /* weight (randomly assigned) */
+ struct treap_node *left, *right; /* left and right subtrees */
+ char *k; size_t kn; /* key pointer and length */
};
#define TREAP_NODE_KEY(n) (((const struct treap_node *)(n))->k + 0)
#define TREAP_NODE_KEYLEN(n) (((const struct treap_node *)(n))->kn + 0)
+/* We can't allocate nodes ourselves, because only the caller knows how.
+ * Instead, insertion is split into two operations: `treap_probe' looks to
+ * see whether a matching node is already in the treap, and returns it if so;
+ * otherwise, it fills in this `treap_path' structure, which is passed back
+ * to `treap_insert' to help it add the fresh node into the treap. (See the
+ * commentary in `treap_probe' and `treap_insert' for the details.)
+ */
#define TREAP_PATHMAX 64
struct treap_path {
struct treap_node **path[TREAP_PATHMAX];
unsigned nsteps;
};
+/* An external iterator for a treap. (See the commentary for
+ * `treap_start_iter' and `treap_next' for the details.)
+ */
struct treap_iter {
struct treap_node *stack[TREAP_PATHMAX];
unsigned sp;
};
extern void treap_init(struct treap */*t*/);
+ /* Initialize the treap T.
+ *
+ * Usually you'd use the static initializer `TREAP_INIT'.
+ */
+
extern void *treap_lookup(const struct treap */*t*/,
const char */*k*/, size_t /*kn*/);
+ /* Look up the KN-byte key K in the treap T.
+ *
+ * Return a pointer to the matching node if one was found, or null
+ * otherwise.
+ */
+
extern void *treap_probe(struct treap */*t*/,
const char */*k*/, size_t /*kn*/,
struct treap_path */*p*/);
+ /* Look up the KN-byte K in the treap T, recording a path in P.
+ *
+ * This is similar to `treap_lookup', in that it returns the
+ * requested node if it already exists, or null otherwise, but it
+ * also records in P information to be used by `treap_insert' to
+ * insert a new node with the given key if it's not there already.
+ */
+
extern void treap_insert(struct treap */*t*/, const struct treap_path */*p*/,
struct treap_node */*n*/,
const char */*k*/, size_t /*kn*/);
+ /* Insert a new node N into T, associating it with the KN-byte key K.
+ *
+ * Use the path data P, from `treap_probe', to help with insertion.
+ */
+
extern void *treap_remove(struct treap */*t*/,
const char */*k*/, size_t /*kn*/);
+ /* Remove the node with the KN-byte K from T.
+ *
+ * Return the address of the node we removed, or null if it couldn't
+ * be found.
+ */
+
extern void treap_start_iter(struct treap */*t*/, struct treap_iter */*i*/);
+ /* Initialize an iterator I over T's nodes. */
+
extern void *treap_next(struct treap_iter */*i*/);
+ /* Return the next node from I, in ascending order by key.
+ *
+ * If there are no more nodes, then return null.
+ */
+
extern void treap_check(struct treap */*t*/);
+ /* Check the treap structure rules for T. */
+
extern void treap_dump(struct treap */*t*/);
+ /* Dump the treap T to standard output, for debugging purposes. */
/*----- Configuration file parsing ----------------------------------------*/
+/* A configuration file. */
struct config {
- struct treap sections;
- struct config_section *head, **tail;
- struct config_section *fallback;
+ struct treap sections; /* treap of sections */
+ struct config_section *head, **tail; /* section list, in creation order */
+ struct config_section *fallback; /* default parent section */
};
#define CONFIG_INIT { TREAP_INIT, 0, 0 }
+/* A configuration section. */
struct config_section {
- struct treap_node _node;
- struct config_section *next;
- struct config_section **parents; size_t nparents;
- struct treap vars;
- struct treap cache;
+ struct treap_node _node; /* treap intrustion */
+ struct config_section *next; /* next section in creation order */
+ struct config_section **parents; size_t nparents; /* vector of parents */
+ struct treap vars; /* treap of variables */
+ struct treap cache; /* inheritance cache */
};
#define CONFIG_SECTION_NAME(sect) TREAP_NODE_KEY(sect)
#define CONFIG_SECTION_NAMELEN(sect) TREAP_NODE_KEYLEN(sect)
+/* An entry in a section's inheritance cache: see `search_recursive' for
+ * details.
+ */
struct config_cache_entry {
- struct treap_node _node;
- unsigned f;
-#define CF_OPEN 1u
- struct config_var *var;
+ struct treap_node _node; /* treap intrusion */
+ unsigned f; /* flags */
+#define CF_OPEN 1u /* traps inheritance cycles */
+ struct config_var *var; /* pointer to inherited variable */
};
+/* A configuration variable. */
struct config_var {
- struct treap_node _node;
- char *file; unsigned line;
- char *val; size_t n;
- unsigned f;
+ struct treap_node _node; /* treap intrusion */
+ char *file; unsigned line; /* source location, or null/0 */
+ char *val; size_t n; /* value pointer and length */
+ unsigned f; /* flags */
+#define CF_LITERAL 1u /* value should not be expanded */
+#define CF_EXPAND 2u /* traps expansion cycles */
+#define CF_OVERRIDE 4u /* override settings from files */
};
#define CONFIG_VAR_NAME(var) TREAP_NODE_KEY(var)
#define CONFIG_VAR_NAMELEN(var) TREAP_NODE_KEYLEN(var)
-#define CF_LITERAL 1u
-#define CF_EXPAND 2u
-#define CF_OVERRIDE 4u
+/* A section iterator.
+ *
+ * (Sections are visited in the order in which they were created.)
+ */
struct config_section_iter {
- struct config_section *sect;
+ struct config_section *sect; /* next section to return */
};
+/* A variable iterator.
+ *
+ * (Variables are visited in lexicographical order.)
+ */
struct config_var_iter {
struct treap_iter i;
};
+/* Common flags. */
+#define CF_CREAT 1u /* create section or variable */
+#define CF_INHERIT 2u /* look up variable in parents */
+
extern void config_init(struct config */*conf*/);
+ /* Initialize the configuration state CONF.
+ *
+ * Usually you'd use the static initializer `CONFIG_INIT'.
+ */
extern struct config_section *config_find_section(struct config */*conf*/,
unsigned /*f*/,
const char */*name*/);
+ /* Find and return the section with null-terminated NAME in CONF.
+ *
+ * If no section is found, the behaviour depends on whether
+ * `CF_CREAT' is set in F: if so, an empty section is created and
+ * returned; otherwise, a null pointer is returned.
+ */
+
extern struct config_section *config_find_section_n(struct config */*conf*/,
unsigned /*f*/,
const char */*name*/,
size_t /*sz*/);
-#define CF_CREAT 1u
+ /* Find and return the section with the given SZ-byte NAME in CONF.
+ *
+ * This works like `config_find_section', but with an explicit length
+ * for the NAME rather than null-termination.
+ */
extern void config_set_fallback(struct config */*conf*/,
struct config_section */*sect*/);
+ /* Set the fallback section for CONF to be SECT.
+ *
+ * That is, if a section has no explicit parents, then by default it
+ * will have a single parent which is SECT. If SECT is null then
+ * there is no fallback section, and sections which don't have
+ * explicitly specified parents have no parents at all. (This is the
+ * default situation.)
+ */
+
extern void config_set_parent(struct config_section */*sect*/,
struct config_section */*parent*/);
+ /* Arrange that SECT has PARENT as its single parent section.
+ *
+ * If PARENT is null, then arrange that SECT has no parents at all.
+ * In either case, any `@parents' setting will be ignored.
+ */
extern void config_start_section_iter(struct config */*conf*/,
struct config_section_iter */*i*/);
+ /* Initialize I to iterate over the sections defined in CONF. */
+
extern struct config_section *config_next_section
(struct config_section_iter */*i*/);
+ /* Return the next section from I, in order of creation.
+ *
+ * If there are no more sections, then return null.
+ */
extern struct config_var *config_find_var(struct config */*conf*/,
struct config_section */*sect*/,
unsigned /*f*/,
const char */*name*/);
+ /* Find and return the variable with null-terminated NAME in SECT.
+ *
+ * If `CF_INHERIT' is set in F, then the function searches the
+ * section's parents recursively; otherwise, it only checks to see
+ * whether the variable is set directly in SECT.
+ *
+ * If no variable is found, the behaviour depends on whether
+ * `CF_CREAT' is set in F: if so, an empty variable is created and
+ * returned; otherwise, a null pointer is returned.
+ *
+ * Setting both `CF_INHERIT' and `CF_CREAT' is not useful.
+ */
+
extern struct config_var *config_find_var_n(struct config */*conf*/,
struct config_section */*sect*/,
unsigned /*f*/,
const char */*name*/,
size_t /*sz*/);
-#define CF_INHERIT 2u
-
-extern void config_set_var(struct config */*conf*/,
- struct config_section */*sect*/, unsigned /*f*/,
- const char */*name*/, const char */*value*/);
-extern void config_set_var_n(struct config */*conf*/,
- struct config_section */*sect*/, unsigned /*f*/,
- const char */*name*/, size_t /*namelen*/,
- const char */*value*/, size_t /*valuelen*/);
-extern void config_start_var_iter(struct config_section */*sect*/,
+ /* Find and return the variable with the given SZ-byte NAME in SECT.
+ *
+ * This works like `config_find_var', but with an explicit length for
+ * the NAME rather than null-termination.
+ */
+
+extern struct config_var *config_set_var(struct config */*conf*/,
+ struct config_section */*sect*/,
+ unsigned /*f*/,
+ const char */*name*/,
+ const char */*value*/);
+ /* Set variable NAME to VALUE in SECT, with associated flags F.
+ *
+ * The names are null-terminated. The flags are variable flags: see
+ * `struct config_var' for details. Returns the variable.
+ *
+ * If the variable is already set and has the `CF_OVERRIDE' flag,
+ * then this function does nothing unless `CF_OVERRIDE' is /also/ set
+ * in F.
+ */
+
+extern struct config_var *config_set_var_n(struct config */*conf*/,
+ struct config_section */*sect*/,
+ unsigned /*f*/,
+ const char */*name*/,
+ size_t /*namelen*/,
+ const char */*value*/,
+ size_t /*valuelen*/);
+ /* As `config_set_var', except that the variable NAME and VALUE have
+ * explicit lengths (NAMELEN and VALUELEN, respectively) rather than
+ * being null-terminated.
+ */
+
+extern void config_start_var_iter(struct config */*conf*/,
+ struct config_section */*sect*/,
struct config_var_iter */*i*/);
+ /* Initialize I to iterate over the variables directly defined in
+ * SECT.
+ */
+
extern struct config_var *config_next_var(struct config_var_iter */*i*/);
+ /* Return next variable from I, in ascending lexicographical order.
+ *
+ * If there are no more variables, then return null.
+ */
extern int config_read_file(struct config */*conf*/, const char */*file*/,
unsigned /*f*/);
-extern int config_read_dir(struct config */*conf*/,
- const char */*dir*/, unsigned /*f*/);
+#define CF_NOENTOK 1u
+ /* Read and parse configuration FILE, applying its settings to CONF.
+ *
+ * If all goes well, the function returns 0. If the file is not
+ * found, then the behaviour depends on whether `CF_NOENTOK' is set
+ * in F: if so, then the function simply returns -1. Otherwise, a
+ * fatal error is reported. Note that this /only/ applies if the
+ * file does not exist (specifically, opening it fails with `ENOENT')
+ * -- any other problems are reported as fatal errors regardless of
+ * the flag setting.
+ */
+
extern void config_read_env(struct config */*conf*/,
struct config_section */*sect*/);
-#define CF_NOENTOK 1u
+ /* Populate SECT with environment variables.
+ *
+ * Environment variables are always set with `CF_LITERAL'.
+ */
extern void config_subst_string(struct config */*config*/,
struct config_section */*home*/,
const char */*what*/,
const char */*p*/, struct dstr */*d*/);
+ /* Expand substitutions in a string.
+ *
+ * Expand the null-terminated string P relative to the HOME section,
+ * using configuration CONFIG, and appending the result to dynamic
+ * string D. Blame WHAT in any error messages.
+ */
+
extern char *config_subst_string_alloc(struct config */*config*/,
struct config_section */*home*/,
const char */*what*/,
const char */*p*/);
+ /* Expand substitutions in a string.
+ *
+ * Expand the null-terminated string P relative to the HOME section,
+ * using configuration CONFIG, returning the result as a freshly
+ * malloc(3)ed string. Blame WHAT in any error messages.
+ */
+
extern void config_subst_var(struct config */*config*/,
struct config_section */*home*/,
struct config_var */*var*/,
struct dstr */*d*/);
+ /* Expand substitutions in a variable.
+ *
+ * Expand the value of the variable VAR relative to the HOME section,
+ * using configuration CONFIG, appending the result to dynamic string
+ * D.
+ */
+
extern char *config_subst_var_alloc(struct config */*config*/,
struct config_section */*home*/,
struct config_var */*var*/);
+ /* Expand substitutions in a variable.
+ *
+ * Expand the value of the variable VAR relative to the HOME section,
+ * using configuration CONFIG, returning the result as a freshly
+ * malloc(3)ed string.
+ */
+
extern void config_subst_split_var(struct config */*config*/,
struct config_section */*home*/,
struct config_var */*var*/,
struct argv */*av*/);
+ /* Expand substitutions in a variable and split into words.
+ *
+ * Expand and word-split the value of the variable VAR relative to
+ * the HOME section, using configuration CONFIG, appending the
+ * resulting words into the vector AV.
+ */
/*----- That's all, folks -------------------------------------------------*/