[TOC]

工程中常用的demo库

//巧妙：删除字符串的首尾多余的字符，如空格 //str为字符串，delimiter也可为字符串 //strchr函数：前参数为字符串，后参数为单个字符 char trim(char str, const char* delimiter) { if (str == 0 || str[0] == 0) { return str; }

char* p1 = str;
char* p2 = NULL;
int len;


len = strlen(p1);
p2 = p1 + len - 1;
while (strchr(delim, *p1))
    p1++;
if(p1>p2)
{
    return NULL;
}
if (*p1 == 0)
    return p1;


while (strchr(delim, *p2))
    p2--;
if(p2<str)
{
    return NULL;
}
*(p2+1) = 0;
return p1;

}

/* 配置文件 [basic] name=hj age=22 sex=fale

[midle] phone=110 email=110@163.com

[senior] address=chongqing school=whu / int config_file_get(const char filename, const char section, const char key, char value) { FILE file = 0; char buff[1024]; char line = 0; int length = 0; int sec_len = strlen(section); int key_len = strlen(key); char pos = 0; int findflag = 0; //0: none-find section, 1:find section, but none-find key, 2:find key

file = fopen(filename, "rt");
if (!file)
    return 0;

while(!feof(file))
{
    line = buff;
    if (0 == fgets(line, sizeof(buff), file))
        goto __end;
    trim(line, " \r\n\t");

    if (line[0]=='['
            && line[strlen(line)-1]==']'
       )
    {
        if (0 == findflag
                && strncmp(&line[1], section, sec_len)==0
                && line[sec_len+1]==']'
           )
        {
            findflag = 1;
        }
        else
        {
            findflag = 0;
        }
        continue;
    }

    if (1 == findflag)
    {
        pos = strchr(line, '=');
        if (pos)
        {
            *pos = 0;
            if (strncmp(trim(line, " \r\n\t"), key, key_len)==0)
            {
                pos++;
                findflag = 2;
            }
        }
    }

    if (2 == findflag)
    {
        char* v = trim(pos, " \r\n\t");
        length = strlen(v);
        strcpy(value, v);
        goto __end;
    }
}

__end: if (file) { fclose(file); } return length; }

static int is_power_of_2(uint32_t n) { return (n != 0 && ((n & (n - 1)) == 0)); }

```