php addslashes函数最终对应的c函数为:
3244 PHPAPI char *php_addslashes_ex(char *str, int length, int *new_length, int should_free, int ignore_sybase TS RMLS_DC)
3245 {
3246 /* maximum string length, worst case situation */
3247 char *new_str;
3248 char *source, *target;
3249 char *end;
3250 int local_new_length;
3251
3252 if (!new_length) {
3253 new_length = &local_new_length;
3254 }
3255 if (!str) {
3256 *new_length = 0;
3257 return str;
3258 }
3259 new_str = (char *) safe_emalloc(2, (length ? length : (length = strlen(str))), 1);
3260 source = str;
3261 end = source + length;
3262 target = new_str;
3263
3264 if (!ignore_sybase && PG(magic_quotes_sybase)) {
3265 while (source
3266 switch (*source) {
3267 case '\0':
3268 *target++ = '\\';
3269 *target++ = '0';
3270 break;
3271 case '\'':
3272 *target++ = '\'';
3273 *target++ = '\'';
3274 break;
3275 default:
3276 *target++ = *source;
3277 break;
3278 }
3279 source++;
3280 }
3281 } else {
3282 while (source
3283 switch (*source) {
3284 case '\0':
3285 *target++ = '\\';
3286 *target++ = '0';
3287 break;
3288 case '\'':
3289 case '\"':
3290 case '\\':
3291 *target++ = '\\';
3292 /* break is missing *intentionally* */
3293 default:
3294 *target++ = *source;
3295 break;
3296 }
3297
3298 source++;
3299 }
3300 }
3301
3302 *target = 0;
3303 *new_length = target - new_str;
3304 if (should_free) {
3305 STR_FREE(str);
3306 }
3307 new_str = (char *) erealloc(new_str, *new_length + 1);
3308 return new_str;
3309 }
从上面看addslashes函数处理的是单字节的字节。
但是gbk编码是双字节的。而且5c又可以做双字节的低位。

php把负数转为正整数的方法:1、使用abs()函数将负数转为正数,使用intval()函数对正数取整,转为正整数,语法“intval(abs($number))”;2、利用“~”位运算符将负数取反加一,语法“~$number + 1”。

实现方法:1、使用“sleep(延迟秒数)”语句,可延迟执行函数若干秒;2、使用“time_nanosleep(延迟秒数,延迟纳秒数)”语句,可延迟执行函数若干秒和纳秒;3、使用“time_sleep_until(time()+7)”语句。

php字符串有下标。在PHP中,下标不仅可以应用于数组和对象,还可应用于字符串,利用字符串的下标和中括号“[]”可以访问指定索引位置的字符,并对该字符进行读写,语法“字符串名[下标值]”;字符串的下标值(索引值)只能是整数类型,起始值为0。

php除以100保留两位小数的方法:1、利用“/”运算符进行除法运算,语法“数值 / 100”;2、使用“number_format(除法结果, 2)”或“sprintf("%.2f",除法结果)”语句进行四舍五入的处理值,并保留两位小数。

判断方法:1、使用“strtotime("年-月-日")”语句将给定的年月日转换为时间戳格式;2、用“date("z",时间戳)+1”语句计算指定时间戳是一年的第几天。date()返回的天数是从0开始计算的,因此真实天数需要在此基础上加1。

在php中,可以使用substr()函数来读取字符串后几个字符,只需要将该函数的第二个参数设置为负值,第三个参数省略即可;语法为“substr(字符串,-n)”,表示读取从字符串结尾处向前数第n个字符开始,直到字符串结尾的全部字符。

方法:1、用“str_replace(" ","其他字符",$str)”语句,可将nbsp符替换为其他字符;2、用“preg_replace("/(\s|\ \;||\xc2\xa0)/","其他字符",$str)”语句。

查找方法:1、用strpos(),语法“strpos("字符串值","查找子串")+1”;2、用stripos(),语法“strpos("字符串值","查找子串")+1”。因为字符串是从0开始计数的,因此两个函数获取的位置需要进行加1处理。


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Atom editor mac version download
The most popular open source editor

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.