libc.c (2193B)
1 /* 2 * libc-style definitions and functions 3 * 4 * Copyright 2018 IBM Corp. 5 * Author(s): Collin L. Walling <walling@linux.vnet.ibm.com> 6 * 7 * This code is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License as published by the 9 * Free Software Foundation; either version 2 of the License, or (at your 10 * option) any later version. 11 */ 12 13 #include "libc.h" 14 #include "s390-ccw.h" 15 16 /** 17 * atoui: 18 * @str: the string to be converted. 19 * 20 * Given a string @str, convert it to an integer. Leading spaces are 21 * ignored. Any other non-numerical value will terminate the conversion 22 * and return 0. This function only handles numbers between 0 and 23 * UINT64_MAX inclusive. 24 * 25 * Returns: an integer converted from the string @str, or the number 0 26 * if an error occurred. 27 */ 28 uint64_t atoui(const char *str) 29 { 30 int val = 0; 31 32 if (!str || !str[0]) { 33 return 0; 34 } 35 36 while (*str == ' ') { 37 str++; 38 } 39 40 while (*str) { 41 if (!isdigit(*(unsigned char *)str)) { 42 break; 43 } 44 val = val * 10 + *str - '0'; 45 str++; 46 } 47 48 return val; 49 } 50 51 /** 52 * uitoa: 53 * @num: an integer (base 10) to be converted. 54 * @str: a pointer to a string to store the conversion. 55 * @len: the length of the passed string. 56 * 57 * Given an integer @num, convert it to a string. The string @str must be 58 * allocated beforehand. The resulting string will be null terminated and 59 * returned. This function only handles numbers between 0 and UINT64_MAX 60 * inclusive. 61 * 62 * Returns: the string @str of the converted integer @num 63 */ 64 char *uitoa(uint64_t num, char *str, size_t len) 65 { 66 long num_idx = 1; /* account for NUL */ 67 uint64_t tmp = num; 68 69 IPL_assert(str != NULL, "uitoa: no space allocated to store string"); 70 71 /* Count indices of num */ 72 while ((tmp /= 10) != 0) { 73 num_idx++; 74 } 75 76 /* Check if we have enough space for num and NUL */ 77 IPL_assert(len > num_idx, "uitoa: array too small for conversion"); 78 79 str[num_idx--] = '\0'; 80 81 /* Convert int to string */ 82 while (num_idx >= 0) { 83 str[num_idx--] = num % 10 + '0'; 84 num /= 10; 85 } 86 87 return str; 88 }