Written by razrlele
16:59 June 11, 2015
Just an assignment from my Linux programming course.
I have only done a small part of work of the ls command, after all, it’s a program with 400+ lines, if you want to study full source codes of ls command(in which there are 4000+ lines codes), you can get it from here.
Honestly, this program is so much different from the Linux source codes, because I have used STL, which has hardly appeared in the Linux source codes but very helpful to simple codes.
The functions I have finished:
Without any option: 
With option -l: use a long listing format: 
With option -a: do not ignore dotfiles: 
With option -R: show subdirectories: 
With option -f: show files without sorting: 
Show files with using default symbols: 
Besides, this program can also display files beautifully in vertical order, just like the ls command.
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/* * File Name: sls.cpp * Author: razrLeLe * Mail: razrlele@gmail.com */ #include <stdio.h> #include <stdlib.h> #include <dirent.h> #include <string.h> #include <sys/stat.h> #include <memory.h> #include <malloc.h> #include <malloc.h> #include <getopt.h> #include <grp.h> #include <pwd.h> #include <unistd.h> #include <fcntl.h> #include <time.h> #include <error.h> #include <sys/types.h> #include <linux/kdev_t.h> #include <sys/ioctl.h> #include <vector> #include <algorithm> #include <ctype.h> #define OPT_v 0x0001 /* -v check version */ #define OPT_h 0x0002 /* -h check help information */ #define OPT_l 0x0004 /* -l show files with a long listing format */ #define OPT_a 0x0008 /* -a show all files (including dotfiles)*/ #define OPT_R 0x0010 /* -R show sub directory */ #define OPT_f 0x0020 /* -f without sorting the results */ #define DONE_SUCCESS 0 using namespace std; struct winsize w; // the width and height of terminal windows typedef struct _Node { char path[1024]; char name[256]; int length; struct stat st; bool operator < ( const _Node b) const{ int lena = strlen(name), lenb = strlen(b.name); int len = min(lena, lenb); int i; for(i = 0; i < len; i++) if( name[i] != b.name[i]) return tolower(name[i]) < tolower(b.name[i]); return lena < lenb; } } nNode; bool cmp(nNode a, nNode b) { return a < b; } int createlslink(char *path, int flag, vector<nNode> &toShow) { DIR *dp; struct dirent *entry; struct stat statbuf; char abspath[1024]; if(( dp = opendir(path)) == NULL) { fprintf(stderr, "cannot open directory:%s\n", path); return -1; } if( chdir(path) == -1) { fprintf(stderr, "cannot cd directory:%s\n", path); return -2; } if( NULL == getcwd(abspath, 1024)) { fprintf(stderr, "getcwd error!\n"); return -3; } while(( entry = readdir(dp)) != NULL) { lstat(entry->d_name, &statbuf); if(( !(flag & OPT_a)) && (entry->d_name[0] == '.')) continue; else { nNode tmpNode; tmpNode.length = strlen(entry->d_name); strcpy(tmpNode.path, abspath); strcpy(tmpNode.name, entry->d_name); memcpy( &tmpNode.st, &statbuf, sizeof(struct stat)); toShow.push_back(tmpNode); } } if( -1 == chdir("..")) { fprintf(stderr, "cannot cd directory:..\n"); return -3; } if(( closedir(dp)) == -1) { fprintf(stderr, "cannot close dp\n"); return -4; } return DONE_SUCCESS; } void findRowNum(vector<nNode> toShow, int &rownum, vector<int> &colspace) //to show file order vertially { bool ok; rownum = 0; do { ok = true; rownum++; int col_count = 0; for( int i = 0; i < toShow.size(); i += rownum) { int tmpnum = 0; for(int j = i; j < i+rownum; j++)//find max strlen in current col tmpnum = max(tmpnum, (int)strlen(toShow[j].name)); col_count += tmpnum + 2; colspace.push_back(tmpnum + 2); if( col_count > w.ws_col) { colspace.clear(); //rownum is to small ok = false; break; } } }while(!ok); return ; } void format_normal_print(vector<nNode> toShow, int flag) { int rownum; vector<int> colspace; findRowNum(toShow, rownum, colspace); int colnum = colspace.size(); for(int i = 0; i < rownum; i++) { int order = 0, strspace; for(int j = i; j < toShow.size(); j += rownum) { strspace = colspace[order++]; if( ((strcmp(toShow[j].name, ".") == 0 ) || (strcmp(toShow[j].name, "..") == 0 )) && (flag & OPT_a)) { printf("%-*s", strspace, toShow[j].name); } else { if( S_ISDIR(toShow[j].st.st_mode)) printf("\033[;32m%-*s\033[0m", strspace, toShow[j].name); else printf("%-*s", strspace, toShow[j].name); } } printf("\n"); } return ; } void format_long_print( vector<nNode> toShow, int flag) { char buf[12]; struct passwd *password; struct group *grp; struct tm *tm_ptr; char linkfilebuf[1024]; char pathfilename[1024]; char filename[256]; if( toShow.empty()) return ; for( vector<nNode>::iterator p = toShow.begin(); p != toShow.end(); p++) { if( !strcmp(p->name, ".") || !strcmp(p->name, "..")) { printf("%s\n", p->name); } else { /*permission*/ strcpy(pathfilename, p->path); strcpy(filename, p->name); memset(buf, '-', 11); buf[11] = 0; if( S_ISDIR(p->st.st_mode)) buf[0] = 'd'; else if( S_ISCHR(p->st.st_mode)) buf[0] = 'c'; else if( S_ISBLK(p->st.st_mode)) buf[0] = 'b'; else if( S_ISFIFO(p->st.st_mode)) buf[0] = 'p'; else if( S_ISLNK(p->st.st_mode)) buf[0] = 'l'; else if( S_ISSOCK(p->st.st_mode)) buf[0] = 's'; if ( S_IRUSR & p->st.st_mode) buf[1] = 'r'; if ( S_IWUSR & p->st.st_mode) buf[2] = 'w'; if ( S_IXUSR & p->st.st_mode) buf[3] = 'x'; if (S_IRGRP & p->st.st_mode) buf[4] = 'r'; if (S_IRGRP & p->st.st_mode) buf[5] = 'w'; if (S_IXGRP & p->st.st_mode) buf[6] = 'x'; if (S_IROTH & p->st.st_mode) buf[7] = 'r'; if (S_IWOTH & p->st.st_mode) buf[8] = 'w'; if (S_IXOTH & p->st.st_mode) buf[9] = 'x'; printf("%s ", buf); /* link number*/ printf("4d ", p->st.st_nlink); /* owner */ password = getpwuid(p->st.st_uid); if( password) { printf("$s ", password->pw_name); } else { printf("%d ", p->st.st_uid); } /* group */ grp = getgrgid(p->st.st_gid); if( grp) { printf("%s ", grp->gr_name); } else { printf("%d ", p->st.st_gid); } /* file bytes or dev number */ if( S_ISBLK(p->st.st_mode) || S_ISCHR(p->st.st_mode)) { printf("%3u, ", MAJOR(p->st.st_rdev)); printf("%3u ", MINOR(p->st.st_mode)); } else { printf("%7u ", p->st.st_size); } /* time */ tm_ptr = localtime( &(p->st.st_mtime)); printf("%02d-%02d ", tm_ptr->tm_mon + 1, tm_ptr->tm_mday); printf("%02d:%02d ", tm_ptr->tm_hour, tm_ptr->tm_min); /* filename */ if (S_ISDIR(p->st.st_mode)) printf("\033[;34m%s\033[0m\n", filename); else printf("%s ", filename); if( S_ISLNK(p->st.st_mode)) { strcat(pathfilename, "/"); strcat(pathfilename, p->name); int rslt = readlink(pathfilename, linkfilebuf, 1024); if (rslt < 0) { printf("readlink error!\n"); exit(-1); } linkfilebuf[rslt] = '\0'; printf("-> \033[;32m%s\033[0m", linkfilebuf); } printf("\n"); } } return ; } void showlslink(vector<nNode> toShow, int flag) { if ( flag & OPT_l) format_long_print(toShow, flag); else format_normal_print(toShow, flag); return ; } void lspath( char *path, int flag) { char pathname[1024]; char filename[1024]; vector<nNode> toShow; if( (createlslink(path, flag, toShow)) != DONE_SUCCESS) { printf("createlslink error!\n"); return ; } if( !(flag & OPT_f)) sort(toShow.begin(), toShow.end(), cmp); showlslink(toShow, flag); for( vector<nNode>::iterator p = toShow.begin(); p != toShow.end(); p++) { if( S_ISDIR(p->st.st_mode) && (flag & OPT_R)) if( strcmp(p->name, ".") && strcmp(p->name, "..")) { strcpy(pathname, p->path); strcat(pathname, "/"); strcat(pathname, p->name); printf("\033[;32m%s:\033[0m\n", pathname); lspath(pathname, flag); } } return ; } int lspath_with_default(int argc, char** argv, int optind, int listflag, char *path) { vector<nNode> toShow; char pathname[1024]; char filename[256]; struct stat statbuf; for(; optind < argc; optind++){ if( lstat( argv[optind], &statbuf) < 0) { fprintf(stderr, "stat error\n"); return -1; } if( S_ISDIR(statbuf.st_mode)){ lspath(argv[optind], listflag); } else { DIR *dp; struct dirent *entry; if( ( dp = opendir(path)) == NULL) { fprintf(stderr, "cannot open directory(default):%s\n", path); return -1; } while (( entry = readdir(dp)) != NULL){ nNode tmpNode; bool flag = true; if ( strlen(entry->d_name) == strlen(argv[optind])) { int len = strlen(argv[optind]); for( int i = 0; i < len; i++) { if( argv[optind][i] == '?') continue; else if(argv[optind][i] != entry->d_name[i]) { flag = false; break; } } if( !flag) continue; } else continue; tmpNode.length = strlen(entry->d_name); strcpy(tmpNode.path, path); strcpy(tmpNode.name, entry->d_name); memcpy( &(tmpNode.st), &statbuf, sizeof(struct stat)); toShow.push_back(tmpNode); break; } } } if( !(listflag & OPT_f)) sort(toShow.begin(), toShow.end(), cmp); showlslink(toShow, listflag); for( vector<nNode>::iterator p = toShow.begin(); p!= toShow.end(); p++) { if( S_ISDIR(p->st.st_mode) && (listflag & OPT_R)) { if( strcmp(p->name, ".") && strcmp(p->name, "..")){ strcpy(pathname, p->path); strcat(pathname, "/"); strcat(pathname, p->name); printf("\033[;32m%s:\033[0m\n", pathname); lspath(pathname, listflag); } } } return 0; } int main(int argc, char *argv[]) { int opt; char path[1024]; int listflag = 0; struct stat statbuf; ioctl(STDOUT_FILENO, TIOCGWINSZ, &w); // get the size of the window struct option longopts[] = {{"help", 0,NULL, 'h'}, {"version", 0, NULL, 'v'}, {0, 0, 0, 0}}; while ((opt = getopt_long(argc, argv, "afhlvR", longopts, NULL)) != -1) { switch (opt) { case 'a': listflag |= OPT_a; break; case 'f': listflag |= OPT_f; break; case 'h': listflag |= OPT_h; break; case 'l': listflag |= OPT_l; break; case 'v': listflag |= OPT_v; break; case 'R': listflag |= OPT_R; break; case '?': printf("Usage:\n %s -h \n or \n %s --help \nfor help\n", argv[0], argv[0]); exit(-1); } } if (listflag & OPT_h) { printf("Usage: %s -afhlvR [directory1 [directory2],...]\n", argv[0]); return 0; } else if (listflag & OPT_v) { printf("sls version 0.1\nBy razrLeLe\n"); return 0; } if (NULL == getcwd(path, 1024)) return -1; if (optind == argc) { lspath(path, listflag); } else { lspath_with_default(argc, argv, optind, listflag, path); } return 0; } |