[Toybox] implementation of stat for toybox
Kamlendu Shekhar
warior.linux at gmail.com
Sat Dec 8 00:24:09 PST 2012
Sorry Rob. I am extremely sorry for that.
I had modified toys.h in my local system.
I missed to attach that file. Please find the patch for toys.h as
attachment.
Regards,
Kamlendu
On Sat, Dec 8, 2012 at 5:44 AM, Rob Landley <rob at landley.net> wrote:
> On 12/06/2012 04:24:59 AM, Kamlendu Shekhar wrote:
>
>> Hi Rob,
>>
>> I tried to implement stat command as per toybox's standards.
>> Please find it as attachment.
>>
>> It has been tested on x86 CentOS 32 bit and ubuntu 64 bit systems. Option
>> "-Z" has not been implemented as of now. I am working on that.
>>
>> Can you please have a look if it can be accepted by community.
>> Please share your comment if you want me to change it.
>>
>
> Well first of all I compiled it and it didn't work, possibly because this
> C file isn't including sys/vfs.h and neither is toys.h so there's no struct
> statfs defined. I can fix that up, I'm just wondernig how it worked for
> you. (Centos headers auto-including stuff from each other, I guess?)
>
> Let's see:
>
> ------quoted attachment "stat.c"------
>
>> /* vi: set sw=4 ts=4
>> *
>> * stat.c : display file or file system status
>> * anand.sinha85 at gmail.com
>> * Copyright 2012 <warior.linux at gmail.com>
>> *
>>
>
> What's the first email address for? And neither actually has your name
> (which is kinda important in a copyright statement, it's saying who it's
> by).
>
> * See http://pubs.opengroup.org/**onlinepubs/9699919799/**
>> utilities/stat.html<http://pubs.opengroup.org/onlinepubs/9699919799/utilities/stat.html>
>>
>
> File not found.
>
> According to the roadmap this one is from the 'development' group meaning
> it's in neither posix nor LSB but linux from scratch needs it to finish
> building. That's why
> http://landley.net/toybox/**status.html<http://landley.net/toybox/status.html>links to a man page for it, not a standards page.
>
> USE_STAT(NEWTOY(stat, "LZfc", TOYFLAG_BIN))
>> config STAT
>> bool st
>> default y
>> help
>> Usage: stat [OPTION] FILE...
>> display file or file system status
>> -Z, --context
>> print the security context information if available
>>
>
> Toybox hasn't got any selinux support yet. I don't know if selinux support
> is even a good idea. (I note it's creeped into android, presumably because
> the idiots at Red Hat gave somebody money and they overrode all the
> engineers.)
>
> SELINUX is a bit like spraying a boat with WD-40 and calling it a
> submarine.
>
> -f, --file-system
>> display file system status instead of file status
>> -c --format=FORMAT
>> use the specified FORMAT instead of the default; output a
>> newline after each use of FORMAT
>> --help display this help and exit
>> The valid format sequences for files (without --file-system):
>> %a Access rights in octal
>> %A Access rights in human readable form
>> %b Number of blocks allocated (see
>> %B The size in bytes of each block reported by
>> %d Device number in decimal
>> %D Device number in hex
>> %f Raw mode in hex
>> %F File type
>> %G Group name of owner
>> %h Number of hard links
>> %i Inode number
>> %n File name
>> %N Quoted file name with dereference if symbolic link
>> %o I/O block size
>> %s Total size, in bytes
>> %t Major device type in hex
>> %T Minor device type in hex
>> %u User ID of owner
>> %U User name of owner
>> %x Time of last access
>> %X Time of last access as seconds since Epoch
>> %y Time of last modification
>> %Y Time of last modification as seconds since Epoch
>> %z Time of last change
>> %Z Time of last change as seconds since Epoch
>> */
>>
>
> Remarkably complicated command.
>
> #define FOR_stat
>> #include "toys.h"
>> #define SIZE_DATE_TIME_STAT 36
>> #define access_string(x, s, i) if((x&7) & 1) \
>> s[9 - i * 3] = 'x'; \
>> else \
>> s[9 - i * 3] = '-'; \
>> if(((x&7) >> 1) & 1) \
>> s[9 - (i * 3 + 1)] = 'w'; \
>> else \
>> s[9 - (i * 3 + 1)] = '-'; \
>> if(((x&7) >> 2) & 1) \
>> s[9 - (i * 3 + 2)] = 'r'; \
>> else \
>> s[9 - (i * 3 + 2)] = '-';
>>
>
> I am not happy with the existence of this macro.
>
> I'm also confused by the use of it: get_access_str() defines a local
> variable with the same name as the macro (this apparently works because the
> macro only triggers when it's got parentheses after it), and then there's
> exactly one use of the macro, so it might as well just be inline...?
>
> static char * check_type_file(mode_t, size_t);
>> static char * get_access_str(unsigned long, mode_t);
>> static char * date_stat_format(time_t );
>> static int do_stat(const char *);
>> static int do_statfs(const char *);
>> inline void print_stat_format(char *, int);
>>
>> GLOBALS(
>> char * access_str;
>> char * file_type;
>> struct passwd * user_name; struct group * group_name; struct tm
>> *time_toy;
>> struct stat * toystat;
>> struct statfs * toystatfs;
>> int toy_obj_file_arg;
>> )
>>
>>
>> static int do_stat(const char * file_name){
>> TT.toystat = (struct stat*)malloc(sizeof(struct stat));
>> if(stat(file_name, TT.toystat) < 0){
>> perror_msg("Error: unable to get information about the file,
>> stat\n", file_name);
>>
>
> I note that perror_msg() will do something like:
>
> printf("%s:%s:%s", command_name, your_message, strerror(errno))
>
> So you get something like ":invalid access" appended to the end
> (appropriately localized into the native language). This means we probably
> don't have to say we couldn't access the file because there's going to be a
> message about that, we just have to give the filename.
>
> I've been keeping the hardwired english messages intentionally terse
> because of this, and trying to stick to words like "bad" which are A)
> extremely short, B) easy to remember even for a non-english speaker, C)
> repeated often enough that people will only have to look up a small number
> of words.
>
> toys.exitval = EXIT_FAILURE;
>> }
>> return 0;
>> }
>>
>> static int do_statfs(const char * file_name){
>> TT.toystatfs = (struct statfs *)malloc(sizeof(struct statfs));
>> if(statfs(file_name, TT.toystatfs) < 0){
>> perror_msg("Error: unable to get information about the file,
>> statfs\n", file_name);
>>
>
> Same as above. And it's more useful to say the filename here if there's
> three or four on the command line and only one fails, or if it fails in a
> script...
>
> perror_msg("statfs '%s'", file_name);
>
> (In this case the command has an awful lot of hardwired english text built
> into it.
>
> toys.exitval = EXIT_FAILURE;
>> }
>> return 0;
>> }
>>
>> static char * check_type_file(mode_t mode, size_t size){
>> if(S_ISREG(mode)){
>> if(size)
>> return "regular file";
>> return "regular empty file";
>> }
>> if(S_ISDIR(mode))
>> return "directory";
>> if(S_ISCHR(mode))
>> return "character device";
>> if(S_ISBLK(mode))
>> return "block device";
>> if(S_ISFIFO(mode))
>> return "FIFO (named pipe)";
>> if(S_ISLNK(mode))
>> return "symbolic link";
>> if(S_ISSOCK(mode))
>> return "socket";
>> }
>>
>
> I'm tempted to try to reuse the endtype() code from ls here, possibly have
> something in lib/lib.c that returns a type number 0-6 and then have ls use
> that to index a string of "/@*|=" and have this use an array of char **blah
> ={"file", "directory"...
>
> But that's cleanup for later...
>
> static char * get_access_str(unsigned long pernission, mode_t mode){
>> static char access_string[10];
>> int i;
>> if(S_ISDIR(mode))
>> access_string[0] = 'd';
>> else
>> access_string[0] = '-';
>> for(i = 0; i < 3; i++){
>> access_string(pernission >> (i * 3) & 7, access_string, i);
>> }
>> access_string[10] = '\0';
>> return access_string;
>> }
>>
>
> Mentioned above. And now that I look more closely, this is the same
> general mode logic as ls -l so I should definitely move that to lib/lib.c
> and combine the uses...
>
> static char * date_stat_format(time_t time){
>> static char buf[SIZE_DATE_TIME_STAT];
>> strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S.000000000",
>> localtime(&time));
>> return buf;
>> }
>>
>
> The host implementation doesnt' do .000000000, it actually shows
> nanoseconds. I believe that's %N these days.
>
> inline void print_stat_format(char *format, int flag){
>> format++;
>> switch(*format){
>> case 'a':
>> if(flag)
>> xprintf("%lu\n", TT.toystatfs->f_bavail);
>> else
>> xprintf("%04lo\n",TT.toystat->**st_mode &
>> (S_ISUID|S_ISGID|S_ISVTX|S_**IRWXU|S_IRWXG|S_IRWXO));
>> break;
>> case 'A':
>> xprintf("%s\n",TT.access_str);
>> break;
>> case 'b':
>> if(flag)
>> xprintf("%lu\n", TT.toystatfs->f_blocks);
>> else
>> xprintf("%llu\n", TT.toystat->st_blocks);
>> break;
>> case 'B':
>> xprintf("%lu\n", TT.toystat->st_blksize);
>> break;
>> case 'c':
>> if(flag)
>> xprintf("%lu\n", TT.toystatfs->f_files);
>> break;
>> case 'C':
>> xprintf("Currently feature is not supported\n");
>> break;
>> case 'd':
>> if(flag)
>> xprintf("%lu\n", TT.toystatfs->f_ffree);
>> else
>> xprintf("%ldd\n", TT.toystat->st_dev);
>> break;
>> case 'D':
>> xprintf("%llxh\n", TT.toystat->st_dev);
>> break;
>> case 'f':
>> if(flag)
>> xprintf("%lu\n", TT.toystatfs->f_bfree);
>> else
>> xprintf("%lx\n", TT.toystat->st_mode);
>> break;
>> case 'F':
>> xprintf("%s\n", TT.file_type);
>> break;
>> case 'g':
>> xprintf("%lu\n", TT.toystat->st_uid);
>> break;
>> case 'G':
>> xprintf("%8s\n", TT.user_name->pw_name);
>> break;
>> case 'h':
>> xprintf("%lu\n", TT.toystat->st_nlink);
>> break;
>> case 'i':
>> if(flag)
>> xprintf("%d%d\n", TT.toystatfs->f_fsid.__val[0],
>> TT.toystatfs->f_fsid.__val[1])**;
>> else
>> xprintf("%llu\n", TT.toystat->st_ino);
>> break;
>> case 'l':
>> if(flag)
>> xprintf("need to implement\n");
>> break;
>> case 'n':
>> xprintf("%s\n", toys.optargs[TT.toy_obj_file_**arg]);
>> break;
>> case 'N':
>> xprintf("`%s\n'", toys.optargs[TT.toy_obj_file_**arg]);
>> break;
>> case 'o':
>> xprintf("%lu\n", TT.toystat->st_blksize);
>> break;
>> case 's':
>> if(flag)
>> xprintf("%d\n", TT.toystatfs->f_frsize);
>> else
>> xprintf("%llu\n", TT.toystat->st_size);
>> break;
>> case 'S':
>> if(flag)
>> xprintf("%d\n", TT.toystatfs->f_bsize);
>> break;
>> case 't':
>> if(flag)
>> xprintf("%lx\n", TT.toystatfs->f_type);
>> break;
>> case 'T':
>> if(flag)
>> xprintf("Needs to be implemented\n");
>> break;
>> case 'u':
>> xprintf("%lu\n", TT.toystat->st_uid);
>> break;
>> case 'U':
>> xprintf("%8s\n", TT.user_name->pw_name);
>> break;
>> case 'x':
>> xprintf("%s\n", date_stat_format(TT.toystat->**st_atime));
>> break;
>> case 'X':
>> xprintf("%llu\n", TT.toystat->st_atime);
>> break;
>> case 'y':
>> xprintf("%s\n", date_stat_format(TT.toystat->**st_mtime));
>> break;
>> case 'Y':
>> xprintf("%llu\n", TT.toystat->st_mtime);
>> break;
>> case 'z':
>> xprintf("%s\n", date_stat_format(TT.toystat->**st_ctime));
>> break;
>> case 'Z':
>> xprintf("%llu\n", TT.toystat->st_ctime);
>> default:
>> xprintf("%c\n", *format);
>> break;
>> }
>> exit(0);
>> }
>>
>
> Ok, there has _got_ to be a way to turn that into table driven logic.
>
> But again, that's a later cleanup.
>
> Um... exit(0)? That ignores toys.exitval, the stat command can take more
> than one input file, and... I think that's leftover debug code?
>
> void stat_main(void){
>> int stat_flag_Z = 0, stat_flag_f = 0, stat_flag_c = 0, stat_format =
>> 0;
>> if(toys.optargs){
>> if(toys.optflags & 1){
>>
>
> There are automatically generated FLAG_ macros now. See commit 674, which
> included an update to code.html describing them:
>
> http://landley.net/hg/toybox/**rev/674#l55.71<http://landley.net/hg/toybox/rev/674#l55.71>
>
> stat_flag_c = 1;
>> TT.toy_obj_file_arg = 1;
>> stat_format = 1;
>> }
>> if(toys.optflags & (1 << 1)){
>> stat_flag_f = 1;
>> if(do_statfs(toys.optargs[TT.**toy_obj_file_arg]) != 0)
>> xprintf("Error STATFS\n");
>> }else
>> if(do_stat(toys.optargs[TT.**toy_obj_file_arg]) != 0)
>> xprintf("Error STAT\n");
>> if(toys.optflags & (1 << 2)){
>> stat_flag_Z = 1;
>> xprintf("SELinux feature has not been implemented so
>> far..\n");
>> }
>> }
>>
>
> These xprintf() calls A) go to stdout instead of stderr (the x part just
> aborts if stdout can't accept the output due to -EPIPE or device full or
> something), B) don't set the error return value, C) don't stop the program.
>
> I've pondered having perror_msg() set the error return value itself, I
> just haven't yet because there might be instances where we _don't_ want
> that. It's one of those "at some point I need to spend half an hour on
> this" things that tend to accumulate on my todo list...
>
> // function to check the type/mode of file
>> if(!stat_flag_f){
>> TT.file_type = check_type_file(TT.toystat->**st_mode,
>> TT.toystat->st_size);
>> // check user and group name
>> TT.user_name = getpwuid(TT.toystat->st_uid);
>> TT.group_name = getgrgid(TT.toystat->st_gid);
>> // function to get access in human readable format
>> TT.access_str = get_access_str((TT.toystat->**st_mode &
>> (S_ISUID|S_ISGID|S_ISVTX|S_**IRWXU|S_IRWXG|S_IRWXO)),
>> TT.toystat->st_mode);
>> TT.time_toy = gmtime(&(TT.toystat->st_atime)**);
>> }
>>
>
> Why are these globals if you're just going to print them later in the same
> function?
>
> if(!(stat_flag_f |stat_flag_Z)){
>> if(stat_format)
>> print_stat_format(toys.**optargs[0], stat_flag_f);
>> xprintf(" File: `%s'\n", toys.optargs[TT.toy_obj_file_**arg]);
>> xprintf(" Size: %llu\t Blocks: %llu\t IO Blocks: %lu\t",
>> TT.toystat->st_size, TT.toystat->st_blocks, TT.toystat->st_blksize);
>> xprintf("%s\n", TT.file_type);
>> xprintf("Device: %llxh\t Inode: %llu\t Links: %lu\n",
>> TT.toystat->st_dev, TT.toystat->st_ino, TT.toystat->st_nlink);
>> xprintf("Access: (%04lo/%s)\tUid: (%lu/%8s)\tGid: (%lu/%8s)\n",
>> (TT.toystat->st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_**IRWXU|S_IRWXG|S_IRWXO)),
>> TT.access_str, TT.toystat->st_uid, TT.user_name->pw_name,
>> TT.toystat->st_gid, TT.group_name->gr_name);
>> xprintf("Access: %s\nModify: %s\nChange: %s\n",
>> date_stat_format(TT.toystat->**st_atime), date_stat_format(TT.toystat->**st_mtime),
>> date_stat_format(TT.toystat->**st_ctime));
>> }else if(stat_flag_f){
>> // implementation of statfs -f, file system
>> if(stat_format)
>> print_stat_format(toys.**optargs[0], stat_flag_f);
>>
>
> First two lines of both if statements are identical, might as well move
> them outside the if and have one. (I'm aware that stat_flag_Z means produce
> no output, but I'm not sure that's intentional.)
>
> xprintf(" File: \"%s\"\n", toys.optargs[TT.toy_obj_file_**arg]);
>>
>
> Also the same as above, unless the single quote vs double quote is
> significant?
>
> xprintf(" ID: %d%d Namelen: %ld Type: %lx\n",
>> TT.toystatfs->f_fsid.__val[0], TT.toystatfs->f_fsid.__val[1],
>> TT.toystatfs->f_namelen, TT.toystatfs->f_type);
>> xprintf("Block Size: %d Fundamental block size: %d\n",
>> TT.toystatfs->f_bsize, TT.toystatfs->f_frsize);
>> xprintf("Blocks: Total: %lu\t", TT.toystatfs->f_blocks);
>> xprintf("Free: %lu\t", TT.toystatfs->f_bfree);
>> xprintf("Available: %lu\n", TT.toystatfs->f_bavail);
>> xprintf("Inodes: Total: %lu\t", TT.toystatfs->f_files);
>> xprintf("\tFree: %d\n", TT.toystatfs->f_ffree);
>>
>
> I suspect agglomerating this into a single xprintf() might be more
> readable.
>
> We're grabbing stuff out of files called __val? Really? (Checks man
> page... Ok, __SWORD_TYPE is _long_. There's a standard for this, LP64, that
> says long and pointer are the same on all Linux systems, which is what this
> does. [Writes email to Michael kerrisk to correct man page...])
>
> Rob
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