Implementing "ls -al"

Can someone do me a favour and check if the following code works, i'm away from my linux machine. The following code should hopefully produce an output similar to that of the "ls -al" command.

PHP Code:

#include <stdio.h> #include <sys/types.h> #include <fcntl.h> #include <dirent.h> #include <stdlib.h> #include <time.h> #include <errno.h> #include <string.h> #include <sys/stat.h> #include <pwd.h> #include <grp.h> #include <unistd.h> #define SIZE 256 char* workdir(){ size_t size = FILENAME_MAX; while(1){ char* wdbuf = (char*)malloc(size); if(getcwd(wdbuf,size) == wdbuf) return wdbuf; free(wdbuf); if(errno != ERANGE)return 0; size *=2; } } void printDetails(char *filename){ struct passwd *my_passwd; struct group *my_group; struct stat sbuf; struct tm *strtime; int fdes; unsigned char type ='?'; unsigned char usr[] = "---"; unsigned char grp[] = "---"; unsigned char oth[] = "---"; unsigned char uid[9], gid[9]; unsigned char mod[13]; mode_t mode; char* curdir; time_t now; int year; /*Concatenate dir names*/ curdir = workdir(); strcat(curdir,"/"); strcat(curdir,filename); /*stat the final dir name*/ if(stat(curdir,&sbuf) != -1){ if(S_ISLNK(sbuf.st_mode)){ if(lstat(curdir,&sbuf) == -1){ fprintf(stderr,"Can't stat %s\n",filename); return; } }else if(S_ISREG(sbuf.st_mode)){ if(fstat(fdes,&sbuf) == -1){ fprintf(stderr,"Can't stat %s\n",filename); return; } } }else{ fprintf(stderr,"Can't stat %s\n",filename); return; } /*format information*/ mode = sbuf.st_mode; if( S_ISLNK( mode ) ) type = 'l'; /*symlink*/ else if( S_ISDIR ( mode ) ) type = 'd'; /*directory*/ else if( S_ISCHR ( mode ) ) type = 'c'; /*character raw device*/ else if( S_ISBLK ( mode ) ) type = 'b'; /*block raw device*/ else if( S_ISFIFO( mode ) ) type = 'p'; /*named pipe*/ else if( S_ISSOCK( mode ) ) type = 's'; /*Unix domain socket*/ else if( S_ISREG ( mode ) ) type = '-'; /*regular file*/ if( mode & S_IRUSR ) usr[0] = 'r'; if( mode & S_IWUSR ) usr[1] = 'w'; if( mode & S_IXUSR ) usr[2] = 'x'; if( mode & S_ISUID ) usr[2] = 's'; /* set UID bit*/ if( mode & S_IRGRP ) grp[0] = 'r'; if( mode & S_IWGRP ) grp[1] = 'w'; if( mode & S_IXGRP ) grp[2] = 'x'; if( mode & S_ISGID ) grp[2] = 's'; /* set GID bit*/ if( mode & S_IROTH ) oth[0] = 'r'; if( mode & S_IWOTH ) oth[1] = 'w'; if( mode & S_IXOTH ) oth[2] = 'x'; my_passwd = getpwuid(sbuf.st_uid); if(my_passwd) strncpy(uid,my_passwd->pw_name,8); else snprintf(uid,9,"%d",sbuf.st_uid); my_group = getgrgid(sbuf.st_gid); if(my_group) strncpy(gid,my_group->gr_name,8); else snprintf(gid,9,"%d",sbuf.st_gid); time(&now); year = localtime(&now)->tm_year; strtime = localtime(&sbuf.st_ctime); if(strtime->tm_year == year) strftime(mod,13,"%b %e %R",strtime); else strftime(mod,13,"%b %e %Y",strtime); /*print the details*/ printf("%c%s%s%s %4u %-8s %81u %12s %s\n", type,usr,grp,oth,sbuf.st_nlink, uid,gid,sbuf.st_size,mod,filename); free(curdir); } int main(int argc, char **argv) { int fdes,count,index; char *curdir; struct stat sbuf; struct dirent **direntp; curdir = workdir(); if(argv[1] != '\0'){ if(stat(argv[1], &sbuf) != -1){ if(S_ISDIR(sbuf.st_mode)){ /* Is a directory */ count = scandir(argv[1],&direntp,NULL,alphasort); if(count){ for(index=0; index<count; ++index){ printDetails(direntp[index]->d_name); free(direntp[index]); } }else{ fprintf(stderr,"Can't open %s\n",argv[1]); exit(EXIT_FAILURE); } }else if(S_ISREG(sbuf.st_mode)){ /* Is a regular file */ if((fdes = open(argv[1],O_RDONLY)) != ENOENT){ printDetails(argv[1]); close(fdes); }else printf("Can't open %s reg\n",argv[1]); } }else printf("Can't stat %s\n", argv[1]); }else{ if(stat(curdir,&sbuf) !=-1){ count = scandir(curdir,&direntp,NULL,alphasort); if(count){ for(index=0; index<count; ++index){ printDetails(direntp[index]->d_name); free(direntp[index]); } }else{ fprintf(stderr,"Can't open %s\n",curdir); exit(EXIT_FAILURE); } }else fprintf(stderr,"Can't stat %s\n",curdir); } free(curdir); free(direntp); return EXIT_SUCCESS; }

i tryed it

howdy >pdstatha<,
i didnt spend a whole bunch of time with this but this is what gcc2.96 had to say when i tryed to compile your code.:)

cd /home/Mike/
make -k dir
g++ dir.cpp -o dir
dir.cpp: In function `void printDetails (char *)':
dir.cpp:93: cannot convert `unsigned char *' to `char *' for argument
`1' to `strncpy (char *, const char *, unsigned int)'
dir.cpp:95: cannot convert `unsigned char *' to `char *' for argument
`1' to `snprintf (char *, unsigned int, const char *, ...)'
dir.cpp:99: cannot convert `unsigned char *' to `char *' for argument
`1' to `strncpy (char *, const char *, unsigned int)'
dir.cpp:101: cannot convert `unsigned char *' to `char *' for argument
`1' to `snprintf (char *, unsigned int, const char *, ...)'
dir.cpp:107: cannot convert `unsigned char *' to `char *' for argument
`1' to `strftime (char *, unsigned int, const char *, const tm *)'
dir.cpp:109: cannot convert `unsigned char *' to `char *' for argument
`1' to `strftime (char *, unsigned int, const char *, const tm *)'
dir.cpp: In function `int main (int, char **)':
dir.cpp:127: parse error before `)'
dir.cpp:140: confused by earlier errors, bailing out
make: *** [dir] Error 1

Compilation exited abnormally with code 2 at Wed Mar 6 22:31:03

sorry.

M.R.

Segmentation fault

Heyy all,

Umm itld, now you weren't trying to compile C code with a C++ compiler, now were you?? :-) (!)

That aside, I found only one bug which prevented the program from compiling, on line 126, change those to double quotes i.e argv[1] != ""

Still your program does not run, I get segmentation fault, could there be something shady with your code (I haven't really analysed it but here is the output:

Code:

beg_g@space:~/test > gcc -o lsal lsal.c beg_g@space:~/test > lsal /home Segmentation fault beg_g@space:~/test >

I called the file lsal.c

Cheers.

newbie trick

howdy,

Quote:

Umm itld, now you weren't trying to compile C code with a C++ compiler, now were you?? :-) (!)

hey nobody is perfect.:o

itld asks himself if this is the only stupid newbie trick he will perform today :D

M.R.

Similar code

I just had to write some code for class and it was interesting when I saw this topic. Here is my code:

Code:

mars:$ more writels2.cpp #include <stdio.h> #include <dirent.h> #include <iostream.h> #include <grp.h> #include <iomanip.h> #include <pwd.h> #include <sys/stat.h> #include <sys/types.h> #include <unistd.h> #include <string.h> #include <string> #include <time.h> void showpermiss(struct stat &s, char *p); int main( int argc, char** argv ) { char *p[20]; char buff[20]; char p2[20]; char mdate[30]; char formating = ' '; int counting=1; cin.getline(buff,20); p[0] = strtok(buff," "); DIR *dirp; struct dirent *direntp; dirp = opendir("."); //if(p[0] == NULL) // { while((direntp = readdir(dirp)) != NULL) { if (strcmp(buff, "dir")==0) { struct stat s; stat(direntp->d_name,&s); showpermiss(s, p2); cout<<p2<<" "; // cout<<s.st_mode; cout<<setw(3)<<s.st_nlink; struct passwd *pw = getpwuid(s.st_uid); cout<<setw(9)<<pw->pw_name; struct group * gr = getgrgid(s.st_gid); cout<<setw(8)<<gr->gr_name; cout<<setw(8)<<s.st_size; strcpy(mdate, ctime(&s.st_mtime)); mdate[16] = 0; cout<<" "<<mdate<< " "; //<<ctime(&s.st_mtime); cout<<setw(2)<<direntp->d_name<<endl; }//endif else if (strcmp(buff, "-w")==0) { cout<<direntp->d_name<<endl; }//end if else if (strcmp(buff, "-pause")==0) { if (counting < 26) { struct stat s; stat(direntp->d_name,&s); showpermiss(s, p2); cout<<p2<<" "; cout<<setw(3)<<s.st_nlink; struct passwd *pw = getpwuid(s.st_uid); cout<<setw(9)<<pw->pw_name; struct group * gr = getgrgid(s.st_gid); cout<<setw(8)<<gr->gr_name; cout<<setw(8)<<s.st_size; strcpy(mdate, ctime(&s.st_mtime)); mdate[16] = 0; cout<<" "<<mdate<< " ";//<<ctime(&s.st_mtime); cout<<setw(2)<<direntp->d_name<<endl; counting++; }//end if }//end if else if (strcmp(buff, "-F")==0) { struct stat s; stat(direntp->d_name,&s); cout<<direntp->d_name; if(s.st_mode & S_IFDIR) cout<<"/"<<endl; else if(s.st_mode & S_IFIFO) cout<<"|"<<endl; else if(s.st_mode & S_IFLNK) cout<<"@"<<endl; else if(s.st_mode & S_IFDOOR) cout<<">"<<endl; else if(s.st_mode & S_IFSOCK) cout<<"="<<endl; else if((s.st_mode & S_IFREG) && (s.st_mode & S_IXUSR) || (s.st_mode &S_IXUSR) || (s.st_mode & S_IXGRP) || (s.st_mode & S_IXOTH)) cout<<"*"<<endl; else cout<<"?"<<endl; }//end if }//end while closedir(dirp); // return 0; } void showpermiss(struct stat &s, char *p) { if ( s.st_mode & S_IFIFO) p[0] = 'p'; else if ( s.st_mode & S_IFCHR ) p[0] = 'c'; else if ( s.st_mode & S_IFDIR ) p[0] = 'd'; else if ( s.st_mode & S_IFBLK ) p[0] = 'b'; else p[0] = '-'; p[1] = ( s.st_mode & S_IRUSR ) ? 'r' : '-'; p[2] = ( s.st_mode & S_IWUSR ) ? 'w' : '-'; p[3] = ( s.st_mode & S_IXUSR ) ? 'x' : '-'; p[4] = ( s.st_mode & S_IRGRP ) ? 'r' : '-'; p[5] = ( s.st_mode & S_IWGRP ) ? 'w' : '-'; p[6] = ( s.st_mode & S_IXGRP ) ? 'x' : '-'; p[7] = ( s.st_mode & S_IROTH ) ? 'r' : '-'; p[8] = ( s.st_mode & S_IWOTH ) ? 'w' : '-'; p[9] = ( s.st_mode & S_IXOTH ) ? 'x' : '-'; p[10] = '\0'; }

how?

howdy,
i compiled this with one error, i had to comment out this section, S_IFDOOR undeclared??

Code:

else if(s.st_mode & S_IFDOOR) cout<<">"<<endl;

on but it will not do anything, i am using a command line like this

./similar /home/Mike

but nothing happens. how is this used??

M.R.

Final code

Just an update, i finally got the code working and here it is if ur interested.

Code:

#include <stdio.h> #include <sys/types.h> #include <fcntl.h> #include <dirent.h> #include <stdlib.h> #include <time.h> #include <errno.h> #include <string.h> #include <sys/stat.h> #include <pwd.h> #include <grp.h> #include <unistd.h> /*prototypes*/ char* workdir(void); void printDetails(char* filename,char* path); int main(int argc, char **argv) { int count,index; char *curdir; struct stat sbuf; struct dirent **direntp; if(argv[1] != '\0'){ if(stat(argv[1], &sbuf) != -1){ if(S_ISDIR(sbuf.st_mode)){ /* Is a directory */ count = scandir(argv[1],&direntp,NULL,alphasort); if(count){ char path[FILENAME_MAX]; for(index=0; index<count; ++index){ strcpy(path,argv[1]); printDetails(direntp[index]->d_name,path); free(direntp[index]); } }else{ fprintf(stderr,"Can't open %s\n",argv[1]); exit(EXIT_FAILURE); } }else printDetails(argv[1],NULL); }else fprintf(stderr,"Can't stat %s\n", argv[1]); }else{ curdir = workdir(); printf("%s\n",curdir); if(stat(curdir,&sbuf) !=-1){ count = scandir(curdir,&direntp,NULL,alphasort); if(count){ for(index=0; index<count; ++index){ printDetails(direntp[index]->d_name,NULL); free(direntp[index]); } }else{ fprintf(stderr,"Can't open %s\n",curdir); exit(EXIT_FAILURE); } }else{ fprintf(stderr,"Can't stat %s\n",curdir); exit(EXIT_FAILURE); } free(curdir); } return EXIT_SUCCESS; } char* workdir(){ while(1){ char* wdbuf = (char*)malloc(FILENAME_MAX); if(getcwd(wdbuf,FILENAME_MAX) == wdbuf) return wdbuf; free(wdbuf); if(errno != ERANGE){ fprintf(stderr,"Out of range\n"); return 0; } } } void printDetails(char *filename,char *path){ struct passwd *my_passwd; /*User details*/ struct group *my_group; /*Group details*/ struct stat sbuf; /*File details*/ struct tm *strtime; /*Time format*/ int fdes; /*File descriptor*/ unsigned char type ='?'; /*File type*/ unsigned char usr[] = "---"; /*User Permissions*/ unsigned char grp[] = "---"; /*Group Permissions*/ unsigned char oth[] = "---"; /*Other Permissions*/ unsigned char uid[9], gid[9]; /*User name and Group name*/ unsigned char mod[13]; /*Time information*/ mode_t mode; /*Used to determine type and permission bits*/ char* curdir; /*Used to hold the current working directory*/ char* buf; /*Used to hold a link location*/ time_t now; /*Used to format the time*/ int year; /*Used to format the time*/ /*If path is null stat by the curdir*/ if(path == NULL){ curdir = workdir(); strcat(curdir,"/"); strcat(curdir,filename); if(stat(curdir,&sbuf) != -1){ if(S_ISLNK(sbuf.st_mode)){ if(readlink(curdir,buf,(size_t)FILENAME_MAX) != -1){ if(lstat(buf,&sbuf) == -1){ fprintf(stderr,"Can't stat %s\n",filename); return; } }else fprintf(stderr,"Can't readlink %s\n",filename); }else if(S_ISREG(sbuf.st_mode)){ if((fdes = open(curdir,O_RDONLY)) != ENOENT){ if(fstat(fdes,&sbuf) == -1){ fprintf(stderr,"Can't stat %s\n",filename); return; } close(fdes); }else{ fprintf(stderr,"Can't open %s\n",filename); return; } } }else{ fprintf(stderr,"Can't stat %s\n",filename); return; } free(curdir); /*Otherwise stat by the path provided*/ }else{ strcat(path,"/"); strcat(path,filename); if(stat(path,&sbuf) != -1){ if(S_ISLNK(sbuf.st_mode)){ if(readlink(path,buf,(size_t)FILENAME_MAX) != -1){ if(lstat(buf,&sbuf) == -1){ fprintf(stderr,"Can't stat %s\n",filename); return; } }else fprintf(stderr,"Can't readlink %s\n",filename); }else if(S_ISREG(sbuf.st_mode)){ if((fdes = open(path,O_RDONLY)) != ENOENT){ if(fstat(fdes,&sbuf) == -1){ fprintf(stderr,"Can't stat %s\n",filename); return; } close(fdes); }else{ fprintf(stderr,"Can't open %s\n",filename); return; } } }else{ fprintf(stderr,"Path: %s\n",path); fprintf(stderr,"Can't stat %s\n",curdir); return; } } /*Get file types and permissions*/ mode = sbuf.st_mode; if( S_ISLNK( mode ) ){ type = 'l'; /*symlink*/ printf("%c\n",type);} else if( S_ISDIR ( mode ) ) type = 'd'; /*directory*/ else if( S_ISCHR ( mode ) ) type = 'c'; /*character raw device*/ else if( S_ISBLK ( mode ) ) type = 'b'; /*block raw device*/ else if( S_ISFIFO( mode ) ) type = 'p'; /*named pipe*/ else if( S_ISSOCK( mode ) ) type = 's'; /*Unix domain socket*/ else if( S_ISREG ( mode ) ) type = '-'; /*regular file*/ if( mode & S_IRUSR ) usr[0] = 'r'; if( mode & S_IWUSR ) usr[1] = 'w'; if( mode & S_IXUSR ) usr[2] = 'x'; if( mode & S_ISUID ) usr[2] = 's'; /* set UID bit*/ if( mode & S_IRGRP ) grp[0] = 'r'; if( mode & S_IWGRP ) grp[1] = 'w'; if( mode & S_IXGRP ) grp[2] = 'x'; if( mode & S_ISGID ) grp[2] = 's'; /* set GID bit*/ if( mode & S_IROTH ) oth[0] = 'r'; if( mode & S_IWOTH ) oth[1] = 'w'; if( mode & S_IXOTH ) oth[2] = 'x'; /*Get user information*/ my_passwd = getpwuid(sbuf.st_uid); if(my_passwd != NULL){ strncpy(uid,my_passwd->pw_name,8); uid[8] = '\0'; }else snprintf(uid,9,"%d",sbuf.st_uid); /*Get group information*/ my_group = getgrgid(sbuf.st_gid); if(my_group != NULL){ strncpy(gid,my_group->gr_name,8); gid[8] = '\0'; }else snprintf(gid,9,"%d",sbuf.st_gid); /*Format the time to readable form*/ time(&now); year = localtime(&now)->tm_year; strtime = localtime(&sbuf.st_ctime); if(strtime->tm_year == year) strftime(mod,13,"%b %e %R",strtime); else strftime(mod,13,"%b %e %Y",strtime); /*print the details*/ printf("%c%s%s%s %d %s %s %d\t%s %s\n", type,usr,grp,oth,sbuf.st_nlink, uid,gid,sbuf.st_size,mod,filename); }

it works

howdy pdstatha,
that works very well. compiled and ran with no errors using gcc 2.96/emacs.

M.R.:)

Re: how?

Quote:

Originally posted by itld
howdy,
i compiled this with one error, i had to comment out this section, S_IFDOOR undeclared??

Code:

else if(s.st_mode & S_IFDOOR) cout<<">"<<endl;

on but it will not do anything, i am using a command line like this

./similar /home/Mike

but nothing happens. how is this used??

M.R.

How's it going? What are you running on? I'm running Unix on SunOS 5.8

pdstatha's code

when i tried to compile his code, it said that alphasort was undeclared??

Re: how?

Quote:

Originally posted by itld

on but it will not do anything, i am using a command line like this

./similar /home/Mike

but nothing happens. how is this used??

M.R. [/B]

OH YEAH...to run it, i used a.out and then typed -F to get the formatting characters. to use each other others (dir, -w, and -pause) run a.out again and try to type the command. dont try to run multiples though LoL cuz it wont work :o)

a.out
-F

a.out
-pause

a.out
-w

a.out
dir

Don't know why it does that, it compiles just fine for me. There is one problem with the code though, for some the code which detects a symbolic link does not work correctly. Any ideas??