decode (2) --- perform formatted conversion from character 03/30/80 _C_a_l_l_i_n_g _I_n_f_o_r_m_a_t_i_o_n integer function decode (str, sp, fmt, fp, ap, a1, ..., a10) character str (ARB), fmt (ARB) integer sp, fp, ap untyped a1, ..., a10 Library: vswtlb (standard Subsystem library) _F_u_n_c_t_i_o_n 'Decode' is used to convert a character string to a number of items in various internal formats (e.g. integer, double precision floating point, address, etc.). Its function is similar to the Fortran statement of the same name. The argument 'str' is the character string to be decoded, and 'sp' indicates the position in 'str' at which decoding is to begin. 'Fmt' is a string of format control directives (discussed below), and 'fp' indicates the position in 'fmt' of the first format control directive to be used for decoding. 'A1' through 'a10' (at most) are variables to receive decoded data; 'a2' through 'a10' are optional, and any or all may be omitted. 'Ap' indicates the next variable in the list of 'a1' through 'a10' to receive decoded data. 'Decode' performs the decoding operation until it either runs out of string to decode or of format to control the decoding. The arguments 'sp', 'fp', and 'ap' are always updated to point to the next unused character in 'str', the next unused character in 'fmt', and the next variable in the variable list, respectively. The function return is OK if not all of the format string was used, EOF if all of the format string was used, or ERR if an input string was in error. The format string consists of a series of "format control directives." Each directive controls the conversion of a segment of the character string into some internal form. A directive consists of the format flag character (an asterisk "*") followed by up to three comma-separated option fields, and a single character format specifier. The option fields are normally designated the "width", "base", and "delimiter character" fields. The width field controls the maximum number of characters in the input string to be converted. The base field controls the radix representation assumed for integer fields (and a few other miscellaneous options, discussed below). The delimiter character field specifies a character that may be used to terminate the conversion process for a single variable if it is encountered in the string. The following format specifiers are available: decode (2) - 1 - decode (2) decode (2) --- perform formatted conversion from character 03/30/80 aaa The input string must contain an address of the form "..". The receiv- ing variable must be a two-word address pointer. bbb ooorrr yyy The input string must contain a boolean constant, which may be 1 or 0, TRUE or FALSE, T or F, YES or NO, Y or N. The receiving variable must be of type integer or type logical. ddd ooorrr fff The input string must contain a standard Fortran representation of a double-precision floating-point constant. The receiving variable must be of type long_real or double_precision. ggg None of the input string is examined by this format code. The argument pointer 'ap' is set to the value of the width field; this allows input items to be re- filled or skipped entirely. hhh The input string must contain at least as many charac- ters as are specified by the width field. The given number of characters are then packed into the receiving variable, which must be an array of integers larger than the number of characters divided by two (since there are two characters per word on the Prime.) The base field, if nonzero, specifies a limit on the number of words of the receiving array that will be changed; thus, if the width field is not specified, the entire input string (possibly terminated by the delimiter character) will be packed into the receiving array, but the array will be protected from overrun by the specification of its size in the base field. The code 'h' comes from the Fortran term "hollerith literal," which is the type of the receiving variable. iii The input string must contain a representation of a short (16-bit) integer constant. If the base field is non-zero, it is assumed to be the radix used for representation of the integer. If zero, base 10 is assumed. The base specified in the format directive may be overridden in the input string by giving a radix followed by the letter "r" followed by the desired value, e.g. "2r1001" or "16rA000". The receiving variable must be of type integer. decode (2) - 2 - decode (2) decode (2) --- perform formatted conversion from character 03/30/80 lll The input string must contain a representation of a long (32-bit) integer constant. The syntax and semantics of this form are identical to form 'i' above, with the exception that the receiving variable must be of type long_int (integer*4). nnn The width field specifies the number of newlines in the input string to be skipped. If the end of the input string is encountered, the skipping stops. This code is most often used by the 'input' routine. ppp The syntax and semantics of this form are identical to the 'h' form above, with the exception that a period character (".") will be placed at the end of the receiving array so that its length may be determined at run time. rrr The input string must contain a standard Fortran representation of a single-precision floating point number. The receiving variable must be of type real. sss As many characters as specified by the base field (unless the delimiter character is encountered first) are copied from the input string to the receiving variable, which must be an array of characters. ttt The string pointer variable 'sp' is set to the value of the width field, or to the length of the input string, whichever is shorter. uuu The values of the width, base, and delimiter character fields specified on this directive become the default values for the remainder of the format directives in the format string. vvv The syntax and semantics of this directive are similar to the 'h' directive above, with the exception that the receiving variable must be a PL/I-style character- varying array. decode (2) - 3 - decode (2) decode (2) --- perform formatted conversion from character 03/30/80 xxx The number of characters specified by the width field (unless the delimiter character is encountered first) are skipped; that is, the specified portion of the input string is ignored. _I_m_p_l_e_m_e_n_t_a_t_i_o_n Impossible to explain to the uninitiated reader. Please see the code, and a system guru. _A_r_g_u_m_e_n_t_s _M_o_d_i_f_i_e_d sp, fp, ap, a1-a10 _C_a_l_l_s ctoi, ctop, ctoc, length, ctoa, move$, ctov, gctoi, gctol, ctor, ctod, remark _S_e_e _A_l_s_o input (2), conversion routines ('cto?*') (2) decode (2) - 4 - decode (2)