Convert free-format input into a long integer.
*string char string containing number to be decoded *nstrt int where to start decode (1st = 1) *ireslt int current value of result
*nstrt int advanced to next number *ireslt long result *jflag int status: -1 = -OK, 0 = +OK, 1 = null, 2 = error
1 The reason slaIntin has separate OK status values for + and - is to enable minus zero to be detected. This is of crucial importance when decoding mixed-radix numbers. For example, an angle expressed as deg, arcmin, arcsec may have a leading minus sign but a zero degrees field. 2 A TAB is interpreted as a space. 3 The basic format is the sequence of fields ^, where # is a sign character + or -, and ^ means a string of decimal digits.
. Leading spaces are ignored. . Spaces between the sign and the number are allowed. . Trailing spaces are ignored; the first signifies end of decoding and subsequent ones are skipped.
. Any character other than +,-,0-9 or space may be used to signal the end of the number and terminate decoding. . Comma is recognised by slaIntin as a special case; it is skipped, leaving the pointer on the next character. See 9, below. 6 The sign is optional. The default is +. 7 A "null result" occurs when the string of characters being decoded does not begin with +,- or 0-9, or consists entirely of spaces. When this condition is detected, jflag is set to 1 and ireslt is left untouched. 8 nstrt = 1 for the first character in the string. 9 On return from slaIntin, nstrt is set ready for the next decode - following trailing blanks and any comma. If a delimiter other than comma is being used, nstrt must be incremented before the next call to slaIntin, otherwise all subsequent calls will return a null result.
. there is a + or - but no number; or . the number is larger than LONG_MAX. 11 When an error has been detected, nstrt is left pointing to the character following the last one used before the error came to light. 12 See also slaFlotin and slaDfltin. P.T.Wallace Starlink 17 November 1993