sflcvts.c

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/*  ----------------------------------------------------------------<Prolog>-
    Name:       sflcvts.c
    Title:      Convert a time to a string
    Package:    Standard Function Library (SFL)

    Written:    1996/01/05  iMatix SFL project team <[e-mail]>
    Revised:    1997/09/08

    Copyright:  Copyright (c) 1996-2000 iMatix Corporation
    License:    This is free software; you can redistribute it and/or modify
                it under the terms of the SFL License Agreement as provided
                in the file LICENSE.TXT.  This software is distributed in
                the hope that it will be useful, but without any warranty.
 ------------------------------------------------------------------</Prolog>-*/

#include "prelude.h"                    /*  Universal header file            */
#include "sflconv.h"                    /*  Prototypes for functions         */


/*  ---------------------------------------------------------------------[<]-
    Function: conv_time_str

    Synopsis: Converts a time to a string.  The flags and width control the
    resulting string.  You can use one or more of these flags added together:
    <TABLE>
        FLAG_T_HH_AS_H      Suppress leading zeroes on the hours.
        FLAG_T_MM_AS_M      Suppress leading zeroes on the minutes.
        FLAG_T_SS_AS_S      Suppress leading zeroes on the seconds.
        FLAG_T_CC_AS_C      Suppress leading zeroes on the centiseconds.
        FLAG_T_COMPACT      Show without delimiters.
        FLAG_T_12_HOUR      Append am/pm indicator.
    </TABLE>

    Returns a pointer to a static area holding the string, or NULL if there
    was an error.

    If no flags are used, the width argument gives these results (shown
    as a picture, which is how conv_time_str works - see conv_time_pict):
    <TABLE>
        4_or_less       Error.
        5_to_7          "hh:mm"
        8_to_10         "hh:mm:ss"
        11_or_more      "hh:mm:ss:cc"
    </TABLE>

    If FLAG_T_COMPACT is used, width gives these results:
    <TABLE>
        3_or_less       Error.
        4_to_5          "hhmm"
        6_to_7          "hhmmss"
        8_or_more       "hhmmsscc"
    </TABLE>

    If FLAG_T_12_HOUR is used, width gives these results:
    <TABLE>
        5_or_less       Error.
        6_to_8          "hh:mma"
        9_to_11         "hh:mm:ssa"
        12_or_more      "hh:mm:ss:cca"
    </TABLE>

    If FLAG_T_COMPACT and FLAG_T_12_HOUR are used, width gives these results:
    <TABLE>
        4_or_less       Error.
        5_to_6          "hhmma"
        7_to_8          "hhmmssa"
        9_or_more       "hhmmsscca"
    </TABLE>
    ---------------------------------------------------------------------[>]-*/

char *
conv_time_str (
    long time,
    int  flags,
    char timesep,
    int  width)
{
    char
        delim [2],                      /*  Delimiter string, ":" or ""      */
        picture [13];                   /*  Largest picture: hh:mm:ss:cca    */
    int
        delim_len;
    int
        space_left = width;

    conv_reason = 0;                    /*  No conversion errors so far      */
    if (flags & FLAG_T_COMPACT)
      {
        delim [0] = 0;
        delim_len = 0;
      }
    else
      {
        delim [0] = timesep;
        delim [1] = 0;
        delim_len = 1;
      }
    if (flags & FLAG_T_12_HOUR)
        space_left--;                   /*  Subtract 1 if eventual "a"       */

    /*  Build-up date picture components until we run out of space           */
    strcpy (picture, (flags & FLAG_T_HH_AS_H? "h": "hh"));
    space_left -= 2;

    if (space_left >= delim_len + 2)
      {
        strcat (picture, delim);
        strcat (picture, (flags & FLAG_T_MM_AS_M? "m": "mm"));
        space_left -= delim_len + 2;
      }
    else
        return (NULL);                  /*  Error - space_left is too small  */

    if (space_left >= delim_len + 2)
      {
        strcat (picture, delim);
        strcat (picture, (flags & FLAG_T_SS_AS_S? "s": "ss"));
        space_left -= delim_len + 2;
      }

    if (space_left >= delim_len + 2)
      {
        strcat (picture, delim);
        strcat (picture, (flags & FLAG_T_CC_AS_C? "c": "cc"));
        space_left -= delim_len + 2;
      }

    /*  Append "a" (or "aa" if space) if 12-hour clock wanted                */
    if (flags & FLAG_T_12_HOUR)
        strcat (picture, (space_left == 0? "a": "aa"));

    return (conv_time_pict (time, picture));
}