| 1 | .\" -*-nroff-*- |
| 2 | .de VS |
| 3 | .sp 1 |
| 4 | .in +5n |
| 5 | .ft B |
| 6 | .nf |
| 7 | .. |
| 8 | .de VE |
| 9 | .ft R |
| 10 | .in -5n |
| 11 | .sp 1 |
| 12 | .fi |
| 13 | .. |
| 14 | .TH str 3 "20 June 1999" mLib |
| 15 | .SH NAME |
| 16 | str \- small string utilities |
| 17 | .\" @str_getword |
| 18 | .\" @str_split |
| 19 | .\" @str_sanitize |
| 20 | .SH SYNOPSIS |
| 21 | .nf |
| 22 | .B "#include <mLib/str.h>" |
| 23 | |
| 24 | .BI "char *str_getword(char **" pp ); |
| 25 | .BI "size_t str_split(char *" p ", char *" v "[], size_t " c ", char **" rest ); |
| 26 | .BI "void str_sanitize(char *" d ", const char *" p ", size_t " sz ); |
| 27 | .fi |
| 28 | .SH DESCRIPTION |
| 29 | The header file |
| 30 | .B <mLib/str.h> |
| 31 | contains a few small utility functions for manipulating null-terminated |
| 32 | strings. |
| 33 | .PP |
| 34 | The function |
| 35 | .B str_getword |
| 36 | extracts the next whitespace-delimited word from a string. The |
| 37 | function's argument, |
| 38 | .IR pp , |
| 39 | is the address of a pointer into the string: this pointer is updated by |
| 40 | .B str_getword |
| 41 | so that it can extract the following word on the next call and so on. |
| 42 | The return value is the address of the next word, appropriately null |
| 43 | terminated. A null pointer is returned if the entire remainder of the |
| 44 | string is whitespace. Note that |
| 45 | .B str_getword |
| 46 | modifies the string as it goes, to null-terminate the individual words. |
| 47 | .PP |
| 48 | The function |
| 49 | .B str_split |
| 50 | divides a string into whitespace-separated words. The arguments are as |
| 51 | follows: |
| 52 | .TP |
| 53 | .I p |
| 54 | The address of the string to split. The string is modified by having |
| 55 | null terminators written after each word extracted. |
| 56 | .TP |
| 57 | .I v |
| 58 | The address of an array of pointers to characters. This array will be |
| 59 | filled in by |
| 60 | .BR str_split : |
| 61 | the first entry will point to the first word extracted from the string, |
| 62 | and so on. If there aren't enough words in the string, the remaining |
| 63 | array elements are filled with null pointers. |
| 64 | .TP |
| 65 | .I c |
| 66 | The maxmimum number of words to extract; also, the number of elements in |
| 67 | the array |
| 68 | .IR v . |
| 69 | .TP |
| 70 | .I rest |
| 71 | The address of a pointer in which to store the address of the remainder |
| 72 | of the string. Leading whitespace is removed from the remainder before |
| 73 | storing. If the remainder string is empty, a null pointer is stored |
| 74 | instead. If |
| 75 | .I rest |
| 76 | is null, the remainder pointer is discarded. |
| 77 | .PP |
| 78 | The return value of |
| 79 | .B str_split |
| 80 | is the number of words extracted from the input string. |
| 81 | .PP |
| 82 | The function |
| 83 | .B str_sanitize |
| 84 | copies at most |
| 85 | .I sz \- 1 |
| 86 | characters from the string |
| 87 | .I p |
| 88 | to |
| 89 | .IR d . |
| 90 | The result string is null terminated. Any nonprinting characters in |
| 91 | .I p |
| 92 | are replaced by an underscore |
| 93 | .RB ` _ ' |
| 94 | when written to |
| 95 | .IR d . |
| 96 | .SH EXAMPLES |
| 97 | Given the code |
| 98 | .VS |
| 99 | char p[] = " alpha beta gamma delta "; |
| 100 | char *v[3]; |
| 101 | size_t n; |
| 102 | char *q; |
| 103 | |
| 104 | n = str_split(p, v, 3, &q); |
| 105 | .VE |
| 106 | following the call to |
| 107 | .BR str_split , |
| 108 | .B n |
| 109 | will have the value 3, |
| 110 | .B v[0] |
| 111 | will point to |
| 112 | .RB ` alpha ', |
| 113 | .B v[1] |
| 114 | will point to |
| 115 | .RB ` beta ', |
| 116 | .B v[2] |
| 117 | will point to |
| 118 | .RB ` gamma ' |
| 119 | and |
| 120 | .B rest |
| 121 | will point to |
| 122 | .RB ` delta\ ' |
| 123 | (note the trailing space). |
| 124 | .PP |
| 125 | Similarly, given the string |
| 126 | .B """\ alpha\ \ beta\ """ |
| 127 | instead, |
| 128 | .B n |
| 129 | will be assigned the value 2, |
| 130 | .B v[0] |
| 131 | and |
| 132 | .B v[1] |
| 133 | will have the same values as last time, and |
| 134 | .B v[2] |
| 135 | and |
| 136 | .B rest |
| 137 | will be null. |
| 138 | .SH "SEE ALSO" |
| 139 | .BR mLib (3). |
| 140 | .SH AUTHOR |
| 141 | Mark Wooding, <mdw@nsict.org> |