diplodocus.org Git - nmh/blob - h/fmt_scan.h

   1
   2 /*
   3  * fmt_scan.h -- definitions for fmt_scan()
   4  */
   5
   6 /*
   7  * This structure describes an "interesting" component.  It holds
   8  * the name & text from the component (if found) and one piece of
   9  * auxilary info.  The structure for a particular component is located
  10  * by (open) hashing the name and using it as an index into the ptr array
  11  * "wantcomp".  All format entries that reference a particular component
  12  * point to its comp struct (so we only have to do component specific
  13  * processing once.  e.g., parse an address.).
  14  *
  15  * In previous implementations "wantcomp" was made available to other
  16  * functions, but now it's private and is accessed via functions.
  17  */
  18 struct comp {
  19     char        *c_name;        /* component name (in lower case) */
  20     char        *c_text;        /* component text (if found)      */
  21     struct comp *c_next;        /* hash chain linkage             */
  22     short        c_flags;       /* misc. flags (from fmt_scan)    */
  23     short        c_type;        /* type info   (from fmt_compile) */
  24     union {
  25         struct tws *c_u_tws;
  26         struct mailname *c_u_mn;
  27     } c_un;
  28     int          c_refcount;    /* Reference count                */
  29 };
  30
  31 #define c_tws c_un.c_u_tws
  32 #define c_mn  c_un.c_u_mn
  33
  34 /*
  35  * c_type bits
  36  */
  37 #define CT_ADDR       (1<<0)    /* referenced as address    */
  38 #define CT_DATE       (1<<1)    /* referenced as date       */
  39
  40 /*
  41  * c_flags bits
  42  */
  43 #define CF_TRUE       (1<<0)    /* usually means component is present */
  44 #define CF_PARSED     (1<<1)    /* address/date has been parsed */
  45 #define CF_DATEFAB    (1<<2)    /* datefield fabricated */
  46 #define CF_TRIMMED    (1<<3)    /* Component has been trimmed */
  47
  48 extern int fmt_norm;
  49
  50 /*
  51  * This structure defines one formatting instruction.
  52  */
  53 struct format {
  54     unsigned char f_type;
  55     char          f_fill;
  56     short         f_width;      /* output field width   */
  57     union {
  58         struct comp *f_u_comp;  /* associated component */
  59         char        *f_u_text;  /* literal text         */
  60         char         f_u_char;  /* literal character    */
  61         int          f_u_value; /* literal value        */
  62     } f_un;
  63     short         f_flags;      /* misc. flags          */
  64 };
  65
  66 #define f_skip f_width          /* instr to skip (false "if") */
  67
  68 #define f_comp  f_un.f_u_comp
  69 #define f_text  f_un.f_u_text
  70 #define f_char  f_un.f_u_char
  71 #define f_value f_un.f_u_value
  72
  73 /*
  74  * f_flags bits
  75  */
  76
  77 #define FF_STRALLOC     (1<<0)  /* String has been allocated */
  78 #define FF_COMPREF      (1<<1)  /* Component reference */
  79
  80 /*
  81  * prototypes used by the format engine
  82  */
  83
  84 /*
  85  * Create a new format string.  Arguments are:
  86  *
  87  * form         - Name of format file.  Will be searched by etcpath(), see that
  88  *                function for details.
  89  * format       - The format string to be used if no format file is given
  90  * default_fs   - The default format string to be used if neither form nor
  91  *                format is given
  92  *
  93  * This function also takes care of processing \ escapes like \n, \t, etc.
  94  *
  95  * Returns an allocated format string.
  96  */
  97
  98 char *new_fs (char *form, char *format, char *default_fs);
  99
 100 /*
 101  * Compile a format string into a set of format instructions.  Arguments are:
 102  *
 103  * fstring      - The format string (the "source code").
 104  * fmt          - Returns an allocated array of "struct fmt" elements.  Each
 105  *                struct fmt is one format instruction interpreted by the
 106  *                format engine.
 107  * reset        - If set to true, the format compiler will reset the
 108  *                component hash table.  The component hash table contains
 109  *                all of the references to message components refered to in
 110  *                the format instructions.  If you have multiple format
 111  *                strings that you want to compile and operate on the
 112  *                same message, this should be set to false.
 113  *
 114  * Returns the total number of components referenced by all format instructions
 115  * since the last reset of the hash table.
 116  */
 117
 118 int fmt_compile (char *fstring, struct format **fmt, int reset);
 119
 120 /*
 121  * Interpret a sequence of compiled format instructions.  Arguments are:
 122  *
 123  * format       - Array of format instructions generated by fmt_compile()
 124  * scanl        - Passed-in character array that will contain the output
 125  *                of the format instructions.  Is always terminated with
 126  *                a newline (\n).
 127  * max          - Maximum number of bytes to be written to "scanl" (in other
 128  *                words, the buffer size).  Includes the trailing NUL.
 129  * width        - Maximum number of displayed characters.  Does not include
 130  *                characters marked as nonprinting or (depending on the
 131  *                encoding) bytes in a multibyte encoding that exceed the
 132  *                character's column width.
 133  * dat          - An integer array that contains data used by certain format
 134  *                functions.  Currently the following instructions use
 135  *                dat[]:
 136  *
 137  *              dat[0] - %(msg), %(dat)
 138  *              dat[1] - %(cur)
 139  *              dat[2] - %(size)
 140  *              dat[3] - %(width)
 141  *              dat[4] - %(unseen)
 142  *
 143  * The return value is a pointer to the next format instruction to
 144  * execute, which is currently always NULL.
 145  */
 146
 147 struct format *fmt_scan (struct format *format, char *scanl, size_t max,
 148                          int width, int *dat);
 149
 150 /*
 151  * Free a format structure and/or component hash table.  Arguments are:
 152  *
 153  * format       - An array of format structures allocated by fmt_compile,
 154  *                or NULL.
 155  * reset        - If true, reset and remove all references in the component
 156  *                hash table.
 157  */
 158
 159 void fmt_free (struct format *fmt, int reset);
 160
 161 /*
 162  * Search for a component structure in the component hash table.  Arguments are:
 163  *
 164  * component    - The name of the component to search for.  By convention
 165  *                all component names used in format strings are lower case,
 166  *                but for backwards compatibility this search is done in
 167  *                a case-SENSITIVE manner.
 168  *
 169  * This function returns a "struct comp" corresponding to the named component,
 170  * or NULL if the component is not found in the hash table.
 171  */
 172
 173 struct comp *fmt_findcomp(char *component);
 174
 175 /*
 176  * Search for a component structure in the component hash table.
 177  *
 178  * Identical to fmd_findcomp(), but is case-INSENSITIVE.
 179  */
 180
 181 struct comp *fmt_findcasecomp(char *component);
 182
 183 /*
 184  * Add a component entry to the component hash table
 185  *
 186  * component    - The name of the component to add to the hash table.
 187  *
 188  * If the component is already in the hash table, this function will do
 189  * nothing.  Returns 1 if a component was added, 0 if it already existed.
 190  */
 191
 192 int fmt_addcompentry(char *component);
 193
 194 /*
 195  * Add a string to a component hash table entry.  Arguments are:
 196  *
 197  * component    - The name of the component to add text to.  The component
 198  *                is searched for in a case-INSENSITIVE manner (note that
 199  *                this is different than fmt_findcomp()).  If the component
 200  *                is not found in the hash table, this function will silently
 201  *                return.
 202  * text         - The text to add to a component hash table entry.  Note that
 203  *                if the last character of the existing component
 204  *                text is a newline AND it is marked as an address
 205  *                component (the the CT_ADDR flag is set) existing
 206  *                component buffer is a newline, it will be separated
 207  *                from previous text by ",\n\t"; otherwise if the last
 208  *                character of the previous text is a newline it will
 209  *                simply be seperated by a "\t".  This unusual processing
 210  *                is designed to handle the case where you have multiple
 211  *                headers with the same name (e.g.: multiple "cc:" headers,
 212  *                even though that isn't technically allowed in the RFCs).
 213  *
 214  * This function is designed to be called when you start processing a new
 215  * component.  The function returns the integer value of the hash table
 216  * bucket corresponding to this component.  If there was no entry found
 217  * in the component hash table, this function will return -1.
 218  */
 219
 220 int fmt_addcomptext(char *component, char *text);
 221
 222 /*
 223  * Append to an existing component.  Arguments are:
 224  *
 225  * bucket       - The hash table bucket corresponding to this component,
 226  *                as returned by fmt_addcomp().  If -1, this function will
 227  *                return with no actions performed.
 228  * component    - The component to append text to.  Like fmt_addcomp, the
 229  *                component is searched case-INSENSITIVELY.
 230  * text         - The text to append to the component.  No special processing
 231  *                is done.
 232  *
 233  * This function is designed to be called when you are processing continuation
 234  * lines on the same header (state == FLDPLUS).
 235  */
 236
 237 void fmt_appendcomp(int bucket, char *component, char *text);
 238
 239 /*
 240  * The implementation of the %(formataddr) function.  This is available for
 241  * programs to provide their own local implementation if they wish to do
 242  * special processing (see uip/replsbr.c for an example).  Arguments are:
 243  *
 244  * orig         - Existing list of addresses
 245  * str          - New address(es) to append to list.
 246  *
 247  * This function returns an allocated string containing the new list of
 248  * addresses.
 249  */
 250
 251 char *formataddr(char *orig, char *str);
 252
 253 /*
 254  * The implementation of the %(concataddr) function.  Arguments and behavior
 255  * are the same as %(formataddr).  Again, see uip/replsbr.c to see how you
 256  * can override this behavior.
 257  */
 258
 259 char *concataddr(char *orig, char *str);