* This code is Copyright (c) 2002, by the authors of nmh. See the
* COPYRIGHT file in the root directory of the nmh distribution for
* complete copyright information.
+ *
+ * This code compiles the format strings (documented in mh-format(5)) into
+ * an internal form to be later processed by fmt_scan.c.
+ *
+ * What happens here is that the format strings are parsed and an array
+ * of struct format structures are returned. Each format structure is
+ * a single operation interpreted by the the routines in fmt_scan.c.
+ *
+ * There is a NOT a one-to-one correspondence between format strings and
+ * format instructions; some functions have side effects that can result
+ * in multiple instructions being generated. The exact list of instructions
+ * generated by a format string can be seem with the nmh fmtdump utility.
+ *
+ * A list of format instructions can be found in fmt_compile.h.
+ *
+ * If you wish to add a new function, you will need to do the following
+ * things:
+ *
+ * - Add a new instruction to the list of instructions in fmt_compile.h.
+ * Note that test instructions (starting with FT_IF_S_NULL) have special
+ * handling, so if you are NOT writing a test function then you need
+ * to insert it into the list before that _and_ bump all of the
+ * following instruction numbers.
+ *
+ * - Add the function name to the functable[] array below, and write any
+ * special code that your function may require in terms of parsing
+ * (it very well may not need anything).
+ *
+ * - Add the code in fmt_scan.c to handle your new function.
+ *
+ * - Document the new function in the mh-format(5) man page.
+ *
*/
#include <h/mh.h>
#include <h/tws.h>
#include <h/fmt_scan.h>
#include <h/fmt_compile.h>
+#include <h/mts.h>
-#ifdef TIME_WITH_SYS_TIME
+#ifdef HAVE_SYS_TIME_H
# include <sys/time.h>
-# include <time.h>
-#else
-# ifdef TM_IN_SYS_TIME
-# include <sys/time.h>
-# else
-# include <time.h>
-# endif
#endif
+#include <time.h>
/*
* hash table for deciding if a component is "interesting"
#define TF_NOW 6 /* special - get current unix time */
#define TF_EXPR_SV 7 /* like expr but save current str reg */
#define TF_NOP 8 /* like expr but no result */
+#define TF_MYNAME 9 /* special - get current name of user */
+#define TF_MYHOST 10 /* special - get "local" hostname */
+#define TF_LMBOX 11 /* special - get full local mailbox */
/* ftable->flags */
/* NB that TFL_PUTS is also used to decide whether the test
#define TFL_PUTS 1 /* implicit putstr if top level */
#define TFL_PUTN 2 /* implicit putnum if top level */
+/*
+ * The functable array maps between the text names of format functions and
+ * the format instructions interpreted by the engine in fmt_scan.c.
+ *
+ * The elements of this structure are as follows:
+ *
+ * name - The name of the function as seen in the format string. This is
+ * what maps a particular function name into a format instruction.
+ * type - The type of argument this function expects. Those types are
+ * listed above (with the TF_ prefix). This affects what gets
+ * placed in the format instruction (the f_un union).
+ * f_type - The instruction corresponding to this function (from the list
+ * in fmt_compile.h).
+ * extra - Used by some functions to provide extra data to the compiler.
+ * Uses include:
+ * - Providing an alternate instruction to combine a load
+ * and test operation (see do_if()).
+ * - Passed in f_value in the format instruction to provide
+ * extra information for the engine (see FT_LV_DAT handling
+ * in fmt_scan.c).
+ * - Provide a hint as to preprocessing that is required for
+ * this instruction (see do_name()).
+ * flags - See the definitions for TFL_PUTS & TFL_PUTN above.
+ */
+
struct ftable {
char *name; /* function name */
char type; /* argument type */
{ "putnum", TF_EXPR, FT_NUM, 0, 0 },
{ "putnumf", TF_EXPR, FT_NUMF, 0, 0 },
{ "putaddr", TF_STR, FT_PUTADDR, 0, 0 },
+ { "putlit", TF_STR, FT_STRLIT, 0, 0 },
{ "void", TF_NOP, 0, 0, 0 },
{ "comp", TF_COMP, FT_LS_COMP, 0, TFL_PUTS },
{ "dat", TF_NUM, FT_LV_DAT, 0, TFL_PUTN },
{ "strlen", TF_NONE, FT_LV_STRLEN, 0, TFL_PUTN },
{ "me", TF_MYBOX, FT_LS_LIT, 0, TFL_PUTS },
+ { "myname", TF_MYNAME, FT_LS_LIT, 0, TFL_PUTS },
+ { "myhost", TF_MYHOST, FT_LS_LIT, 0, TFL_PUTS },
+ { "localmbox", TF_LMBOX, FT_LS_LIT, 0, TFL_PUTS },
{ "plus", TF_NUM, FT_LV_PLUS_L, 0, TFL_PUTN },
{ "minus", TF_NUM, FT_LV_MINUS_L, 0, TFL_PUTN },
{ "divide", TF_NUM, FT_LV_DIVIDE_L, 0, TFL_PUTN },
{ "ingrp", TF_COMP, FT_LV_INGRPF, FT_PARSEADDR, TFL_PUTN },
{ "nohost", TF_COMP, FT_LV_NOHOSTF, FT_PARSEADDR, TFL_PUTN },
{ "formataddr", TF_EXPR_SV,FT_FORMATADDR, FT_FORMATADDR, 0 },
+ { "concataddr", TF_EXPR_SV,FT_CONCATADDR, FT_FORMATADDR, 0 },
{ "friendly", TF_COMP, FT_LS_FRIENDLY, FT_PARSEADDR, TFL_PUTS },
{ "mymbox", TF_COMP, FT_LV_COMPFLAG, FT_MYMBOX, TFL_PUTN },
#define PUTLIT(str) do { NEW(FT_LIT,0,0); fp->f_text = (str); } while (0)
#define PUTC(c) do { NEW(FT_CHAR,0,0); fp->f_char = (c); } while (0)
-static char *format_string;
+char *format_string;
static unsigned char *usr_fstring; /* for CERROR */
#define CERROR(str) compile_error (str, cp)
/*
- * external prototypes
- */
-extern char *getusername(void);
-
-/*
* static prototypes
*/
static struct ftable *lookup(char *);
static char *do_if(char *);
+/*
+ * Lookup a function name in the functable
+ */
static struct ftable *
lookup(char *name)
{
fmt_compile(char *fstring, struct format **fmt)
{
register char *cp;
- int i;
+ size_t i;
if (format_string)
free (format_string);
}
+/*
+ * Process functions & components (handle field width here as well
+ */
static char *
do_spec(char *sp)
{
return (cp);
}
+/*
+ * Process a component name. Normally this involves generating an FT_COMP
+ * instruction for the specified component. If preprocess is set, then we
+ * do some extra processing.
+ */
static char *
do_name(char *sp, int preprocess)
{
return (cp);
}
+/*
+ * Generate one or more instructions corresponding to the named function.
+ * The different type of function arguments are handled here.
+ */
static char *
do_func(char *sp)
{
LS(t->f_type, getusername());
break;
+ case TF_MYNAME:
+ LS(t->f_type, getfullname());
+ break;
+
+ case TF_MYHOST:
+ LS(t->f_type, LocalName(0));
+ break;
+
+ case TF_LMBOX:
+ LS(t->f_type, getlocalmbox());
+ break;
+
case TF_NOW:
LV(t->f_type, time((time_t *) 0));
break;
return (cp);
}
+/*
+ * Handle an expression as an argument. Basically we call one of do_name(),
+ * do_func(), or do_if()
+ */
static char *
do_expr (char *sp, int preprocess)
{
return (cp);
}
+/*
+ * I am guessing this was for some kind of loop statement, which would have
+ * looked like %[ .... %]. It looks like the way this would have worked
+ * is that the format engine would have seen that FT_DONE had a 1 in the
+ * f_un.f_un_value and then decided whether or not to continue the loop.
+ * There is no support for this in the format engine, so right now if
+ * you try using it you will reach the FT_DONE and simply stop. I'm leaving
+ * this here in case someone wants to continue the work.
+ */
static char *
do_loop(char *sp)
{
return cp;
}
+/*
+ * Handle an if-elsif-endif statement. Note here that the branching
+ * is handled by the f_skip member of the struct format (which is really
+ * just f_width overloaded). This number controls how far to move forward
+ * (or back) in the format instruction array.
+ */
static char *
do_if(char *sp)
{
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