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1 | .\" Copyright (c) 1990 The Regents of the University of California. |
| 2 | .\" All rights reserved. | |
| 3 | .\" | |
| 4 | .\" This code is derived from software contributed to Berkeley by | |
| 5 | .\" Chris Torek. | |
| 6 | .\" | |
| 7 | .\" %sccs.include.redist.man% | |
| 8 | .\" | |
| 9 | .\" @(#)strtol.3 5.1 (Berkeley) %G% | |
| 10 | .\" | |
| 11 | .TH STRTOL 3 "" | |
| 12 | .UC 7 | |
| 13 | .SH NAME | |
| 14 | strtol \- convert a string to a long integer | |
| 15 | .SH SYNOPSIS | |
| 16 | .B #include <stdlib.h> | |
| 17 | .br | |
| 18 | .B #include <limits.h> | |
| 19 | .PP | |
| 20 | .B "long strtol(char *nptr, char **endptr, int base); | |
| 21 | .SH DESCRIPTION | |
| 22 | .B Strtol | |
| 23 | converts the string in | |
| 24 | .I nptr | |
| 25 | to a | |
| 26 | .B long | |
| 27 | value according to the given | |
| 28 | .IR base , | |
| 29 | which must be between 2 and 36 inclusive, | |
| 30 | or be the special value 0. | |
| 31 | .PP | |
| 32 | The string may begin with an arbitrary amount of white space | |
| 33 | (as determined by | |
| 34 | .BR isspace ; | |
| 35 | see | |
| 36 | .IR ctype (3)), | |
| 37 | followed by a single optional `+' or `-' sign. | |
| 38 | If | |
| 39 | .I base | |
| 40 | is zero or 16, | |
| 41 | the string may then include a `0x' prefix, | |
| 42 | and the number will be read in base 16; otherwise, a zero | |
| 43 | .I base | |
| 44 | is taken as 10 (decimal) unless the next character is `0', | |
| 45 | in which case it is taken as 8 (octal). | |
| 46 | .PP | |
| 47 | The remainder of the string is converted to a | |
| 48 | .B long | |
| 49 | value in the obvious manner, | |
| 50 | stopping at the first character which is not a valid digit | |
| 51 | in the given base. | |
| 52 | (In bases above 10, the letter `A' in either upper or lower case | |
| 53 | represents 10, `B' represents 11, and so forth, with `Z' representing 35.) | |
| 54 | .PP | |
| 55 | If | |
| 56 | .I endptr | |
| 57 | is non nil, | |
| 58 | .B strtol | |
| 59 | stores the address of the first invalid character in | |
| 60 | .IR *endptr . | |
| 61 | If there were no digits at all, however, | |
| 62 | .B strtol | |
| 63 | stores the original value of | |
| 64 | .I nptr | |
| 65 | in | |
| 66 | .IR *endptr . | |
| 67 | (Thus, if | |
| 68 | .I *nptr | |
| 69 | is not '\e0' but | |
| 70 | .IR **endptr | |
| 71 | is '\e0' on return, the entire string was valid.) | |
| 72 | .SH RETURN VALUE | |
| 73 | .B Strtol | |
| 74 | returns the result of the conversion, | |
| 75 | unless the value would underflow or overflow. | |
| 76 | If an underflow occurs, | |
| 77 | .B strtol | |
| 78 | returns | |
| 79 | .BR LONG_MIN . | |
| 80 | If an overflow occurs, | |
| 81 | .B strtol | |
| 82 | returns | |
| 83 | .BR LONG_MAX . | |
| 84 | In both cases, | |
| 85 | .B errno | |
| 86 | is set to | |
| 87 | .BR ERANGE . | |
| 88 | .SH ERRORS | |
| 89 | .TP | |
| 90 | [ERANGE] | |
| 91 | The given string was out of range; the value converted has been clamped. | |
| 92 | .SH SEE ALSO | |
| 93 | atof(3), atoi(3), atol(3), strtod(3), strtoul(3) | |
| 94 | .SH STANDARDS | |
| 95 | .B Strtol | |
| 96 | conforms to ANSI X3.159-1989 (``ANSI C''). | |
| 97 | .SH BUGS | |
| 98 | Ignores the current locale. |