對(duì)于C的語(yǔ)言的字符串比較，目前使用比較多的是將版本分段進(jìn)行比較，下面就是使用C語(yǔ)言實(shí)現(xiàn)的版本比較，可用于物聯(lián)網(wǎng)、嵌入式等的固件版本檢測(cè)。

#define VERSION_PRE_LEN     10

/**
 * 將字符串形式的版本號(hào)轉(zhuǎn)為數(shù)組形式的版本號(hào)
 * @param version 字符串版本號(hào)
 * @param ver_arr 數(shù)組形式版本號(hào)
 * @return
 */
int get_version(char *version, int *ver_arr)
{
    if (version == NULL)
        return -1;

    int index = 0;
    char num_str[VERSION_PRE_LEN];
    char *cur = version;
    char *pos = strchr(version, '.');
    while (pos != '\0') {
        memset(num_str, 0, VERSION_PRE_LEN);
        if (cur == version) {
            memcpy(num_str, cur, pos - cur);
        } else {
            memcpy(num_str, cur + 1, pos - cur);
        }

        ver_arr[index] = atoi(num_str);
        cur = pos;
        pos = strchr(pos + 1, '.');
        index++;
    }

    memset(num_str, 0, VERSION_PRE_LEN);
    memcpy(num_str, cur + 1, version + strlen(version) - cur);
    ver_arr[index] = atoi(num_str);

    return 0;
}

/**
 * 字符串形式的版本號(hào)比較
 * @param version1
 * @param version2
 * @param count 段數(shù)
 * @return 0: version1=version2, 1: version1>version2, -1:version1<version2
 */
int compare_version(char *version1, char *version2, int count)
{
    int ver_arr1[count];
    int ver_arr2[count];

    get_version(version1, ver_arr1);
    get_version(version2, ver_arr2);

    // 一段一段的比較
    for (int index = 0; index < count; index++) {
        if (ver_arr1[index] > ver_arr2[index]) {
            return 1;
        } else if (ver_arr1[index] < ver_arr2[index]) {
            return -1;
        }
    }

    return 0;
}

測(cè)試

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main() 
{
    char version1[] = "42345.724345.2323450.23450.248.25234520";
    char version2[] = "42345.724345.2323450.23450.248.25234520";

    if (compare_version(version1, version2, 6) > 0) {
        printf("version1 > version2");
    } else if (compare_version(version1, version2, 6) < 0) {
        printf("version1 < version2");
    } else {
        printf("version1 = version2");
    }

    return 0;
}