projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| dfdbd267 KB |
1 | /*- |
| 2 | * Copyright (c) 1991 The Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * This code is derived from software contributed to Berkeley by | |
| 6 | * Kenneth Almquist. | |
| 7 | * | |
| 8 | * %sccs.include.redist.c% | |
| 9 | */ | |
| 10 | ||
| 11 | #ifndef lint | |
| 12 | static char sccsid[] = "@(#)mystring.c 5.1 (Berkeley) %G%"; | |
| 13 | #endif /* not lint */ | |
| 14 | ||
| 15 | /* | |
| 16 | * String functions. | |
| 17 | * | |
| 18 | * equal(s1, s2) Return true if strings are equal. | |
| 19 | * scopy(from, to) Copy a string. | |
| 20 | * scopyn(from, to, n) Like scopy, but checks for overflow. | |
| 21 | * strchr(s, c) Find first occurance of c in s. | |
| 22 | * bcopy(from, to, n) Copy a block of memory. | |
| 23 | * number(s) Convert a string of digits to an integer. | |
| 24 | * is_number(s) Return true if s is a string of digits. | |
| 25 | */ | |
| 26 | ||
| 27 | #include "shell.h" | |
| 28 | #include "syntax.h" | |
| 29 | #include "error.h" | |
| 30 | #include "mystring.h" | |
| 31 | ||
| 32 | ||
| 33 | char nullstr[1]; /* zero length string */ | |
| 34 | ||
| 35 | ||
| 36 | /* | |
| 37 | * scopyn - copy a string from "from" to "to", truncating the string | |
| 38 | * if necessary. "To" is always nul terminated, even if | |
| 39 | * truncation is performed. "Size" is the size of "to". | |
| 40 | */ | |
| 41 | ||
| 42 | void | |
| 43 | scopyn(from, to, size) | |
| 44 | register char const *from; | |
| 45 | register char *to; | |
| 46 | register int size; | |
| 47 | { | |
| 48 | ||
| 49 | while (--size > 0) { | |
| 50 | if ((*to++ = *from++) == '\0') | |
| 51 | return; | |
| 52 | } | |
| 53 | *to = '\0'; | |
| 54 | } | |
| 55 | ||
| 56 | ||
| 57 | /* | |
| 58 | * strchr - find first occurrence of a character in a string. | |
| 59 | */ | |
| 60 | ||
| 61 | #ifndef SYS5 | |
| 62 | char * | |
| 63 | mystrchr(s, charwanted) | |
| 64 | char const *s; | |
| 65 | register char charwanted; | |
| 66 | { | |
| 67 | register char const *scan; | |
| 68 | ||
| 69 | /* | |
| 70 | * The odd placement of the two tests is so NUL is findable. | |
| 71 | */ | |
| 72 | for (scan = s ; *scan != charwanted ; ) /* ++ moved down for opt. */ | |
| 73 | if (*scan++ == '\0') | |
| 74 | return NULL; | |
| 75 | return (char *)scan; | |
| 76 | } | |
| 77 | #endif | |
| 78 | ||
| 79 | ||
| 80 | ||
| 81 | /* | |
| 82 | * bcopy - copy bytes | |
| 83 | * | |
| 84 | * This routine was derived from code by Henry Spencer. | |
| 85 | */ | |
| 86 | ||
| 87 | void | |
| 88 | mybcopy(src, dst, length) | |
| 89 | pointer dst; | |
| 90 | const pointer src; | |
| 91 | register int length; | |
| 92 | { | |
| 93 | register char *d = dst; | |
| 94 | register char *s = src; | |
| 95 | ||
| 96 | while (--length >= 0) | |
| 97 | *d++ = *s++; | |
| 98 | } | |
| 99 | ||
| 100 | ||
| 101 | /* | |
| 102 | * prefix -- see if pfx is a prefix of string. | |
| 103 | */ | |
| 104 | ||
| 105 | int | |
| 106 | prefix(pfx, string) | |
| 107 | register char const *pfx; | |
| 108 | register char const *string; | |
| 109 | { | |
| 110 | while (*pfx) { | |
| 111 | if (*pfx++ != *string++) | |
| 112 | return 0; | |
| 113 | } | |
| 114 | return 1; | |
| 115 | } | |
| 116 | ||
| 117 | ||
| 118 | /* | |
| 119 | * Convert a string of digits to an integer, printing an error message on | |
| 120 | * failure. | |
| 121 | */ | |
| 122 | ||
| 123 | int | |
| 124 | number(s) | |
| 125 | const char *s; | |
| 126 | { | |
| 127 | ||
| 128 | if (! is_number(s)) | |
| 129 | error2("Illegal number", (char *)s); | |
| 130 | return atoi(s); | |
| 131 | } | |
| 132 | ||
| 133 | ||
| 134 | ||
| 135 | /* | |
| 136 | * Check for a valid number. This should be elsewhere. | |
| 137 | */ | |
| 138 | ||
| 139 | int | |
| 140 | is_number(p) | |
| 141 | register const char *p; | |
| 142 | { | |
| 143 | do { | |
| 144 | if (! is_digit(*p)) | |
| 145 | return 0; | |
| 146 | } while (*++p != '\0'); | |
| 147 | return 1; | |
| 148 | } |