自己实现的grep程序

在看Nginx代码的时候，经常需要在代码文件中查找一些特定的字符串，觉得系统本身自带的grep输出

格式太丑陋了，又不想去学习那么多繁琐的命令参数，干脆自己实现了一个，感觉还挺好用的。

#include <apue.h>

#define end(s)    ((char *) (s) + strlen(s))

typedef void (*file_handler)(const char *path, void *args);

char content[128];

int main(int argc, char **argv)
{
    int        len;
    char     path[1024], *p;

    assert(argc == 3);

    if (chdir(argv[1]))
        err_sys("chdir error");

    if (getcwd(path, sizeof path) == NULL)
        err_sys("getcwd error");

    p = argv[2];
    len = strlen(p);

    if (len > 2 && *p == '"' && p[len - 1] == '"')
        strncpy(content, p + 1, len - 2);
    else
        strncpy(content, p, len);

    printf("\nSearch directory : %s for string \"%s\"\n", path, content);


    dir_walk(path, grep_file, content);

    printf("\n");

    return 0;
}

void
dir_walk(const char *dname, file_handler handler, void *args)
{
    DIR             *dp;
    struct stat      statbuf;
    struct dirent     *dirp;
    char             fullpath[1024];

    if ((dp = opendir(dname)) == NULL)
        err_sys("opendir %s error", dname);

    while ((dirp = readdir(dp)) != NULL) {
        if (!strcmp(dirp->d_name, ".") ||
                !strcmp(dirp->d_name, ".."))
            continue;

        snprintf(fullpath, sizeof fullpath, "%s/%s", dname, dirp->d_name);

        if (lstat(fullpath, &statbuf) < 0)
            err_sys("lstat error");

        if (S_ISDIR(statbuf.st_mode))
            dir_walk(fullpath, handler, args);
        else
            handler(fullpath, args);
    }

    closedir(dp);
}


static void
grep_file(const char *path, void *data)
{
    int           fd, nline;
    FILE         *fp;

    char        *p, *content;
    char           line[1024];
    static    int     count;

    content = (char *) data;

    if ((fd = open(path, O_RDONLY)) < 0)
        err_sys("file %s open error", path);

    if ((fp = fdopen(fd, "r")) == NULL)
        err_sys("fdopen %s error", path);

    nline = 0;

    while (fgets(line, sizeof line, fp)) {

        nline++;

        if ((p = strstr(line, content)))
            printf("\n%d . %s : %d\n\t%s", ++count, path, nline, line);
    }

    fclose(fp);

    close(fd);
}

 search.zip