stat.c

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/* stat.c Feb 1987 - main, printit, statit
 *
 * stat - a program to perform what the stat(2) call does.  
 *
 * usage: stat [-] [-all] -<field> [-<field> ...] [file1 file2 file3 ...]
 *
 * where   <field> is one of the struct stat fields without the leading "st_".
 *         The three times can be printed out as human times by requesting
 *         -Ctime instead of -ctime (upper case 1st letter).
 *         - means take the file names from stdin.
 *         -0.. means fd0..
 *         no files means all fds.
 *
 * output: if only one field is specified, that fields' contents are printed.
 *         if more than one field is specified, the output is
 *         file filed1: f1val, field2: f2val, etc
 *
 * written: Larry McVoy, (mcvoy@rsch.wisc.edu)  
 */

# define        ALLDEF          /* Make -all default. (kjb) */

# include       <sys/types.h>
# include       <errno.h>
# include       <limits.h>
# include       <stdio.h>
# include       <stdlib.h>
# include       <unistd.h>
# include       <string.h>
# include       <time.h>
# include       <sys/stat.h>
# define        addr(x)         ((void*) &sbuf.x)
# define        size(x)         sizeof(sbuf.x)
# define        equal(s, t)     (strcmp(s, t) == 0)
# ifndef PATH_MAX
#  define       PATH_MAX        1024
# endif
# undef         LS_ADDS_SPACE   /* AT&T Unix PC, ls prints "file[* /]" */
                                /* This makes stat fail. */

# ifndef _MINIX                 /* All but Minix have u_* and st_blocks */
#  define BSD
# endif

# ifndef S_IREAD
#  define S_IREAD       S_IRUSR
#  define S_IWRITE      S_IWUSR
#  define S_IEXEC       S_IXUSR
# endif

char *      arg0;
struct stat sbuf;
extern int  errno;
int         first_file= 1;
#ifndef S_IFLNK
#define lstat   stat
#endif

struct field {
    char* f_name;       /* field name in stat */
    u_char* f_addr;     /* address of the field in sbuf */
    u_short f_size;     /* size of the object, needed for pointer arith */
    u_short f_print;    /* show this field? */
} fields[] = {
    { "dev",            addr(st_dev),           size(st_dev),           0 },
    { "ino",            addr(st_ino),           size(st_ino),           0 },
    { "mode",           addr(st_mode),          size(st_mode),          0 },
    { "nlink",          addr(st_nlink),         size(st_nlink),         0 },
    { "uid",            addr(st_uid),           size(st_uid),           0 },
    { "gid",            addr(st_gid),           size(st_gid),           0 },
    { "rdev",           addr(st_rdev),          size(st_rdev),          0 },
    { "size",           addr(st_size),          size(st_size),          0 },
    { "Atime",          addr(st_atime),         size(st_atime),         0 },
    { "atime",          addr(st_atime),         size(st_atime),         0 },
    { "Mtime",          addr(st_mtime),         size(st_mtime),         0 },
    { "mtime",          addr(st_mtime),         size(st_mtime),         0 },
    { "Ctime",          addr(st_ctime),         size(st_ctime),         0 },
    { "ctime",          addr(st_ctime),         size(st_ctime),         0 },
# ifdef BSD
    { "blksize",        addr(st_blksize),       size(st_blksize),       0 },
    { "blocks",         addr(st_blocks),        size(st_blocks),        0 },
# endif
    { NULL,             0,                      0,                      0 },
};
    
void printstat(struct stat *sbuf, int nprint);
void printit(struct stat* sb, struct field* f, int n);
void rwx(mode_t mode, char *bit);
void usage(void);

int do_readlink=0;

int main(int ac, char** av)
{
    int      i, j, nprint = 0, files = 0;
    char     buf[PATH_MAX], *check;
    int      sym=0, ret=0, from_stdin = 0;
    int      err;
    u_long   fd;

    if ((arg0 = strrchr(av[0], '/')) == NULL) arg0 = av[0]; else arg0++;
#ifdef S_IFLNK
    if (equal(arg0, "lstat")) sym = 1;
    if (equal(arg0, "readlink")) do_readlink = 1;
#endif

    if (ac > 1 && equal(av[i = 1], "-"))
        i++, from_stdin++;

    for (i= 1; i<ac; i++)  {
        if (av[i][0] == '-')  {
            if (equal(av[i], "-")) {
                from_stdin= 1;
                files++;
                continue;
            }
            if (equal("-all", av[i])) {
                for (j=0; fields[j].f_name; j++)
                    nprint++, fields[j].f_print++;
                continue;
            }
            if (equal("-s", av[i])) {
#ifdef S_IFLNK
                sym=1;
#endif
                continue;
            }
            fd = strtoul(av[i]+1, &check, 0);
            if (check != av[i]+1 && *check == '\0')
            {
                files++;
                continue;
            }
            for (j=0; fields[j].f_name; j++) 
                if (equal(fields[j].f_name, &av[i][1])) {
                    nprint++, fields[j].f_print++;
                    break;
                }
            if (!fields[j].f_name) {
                if (!equal("-?", av[i])) {
                    fprintf(stderr, "stat: %s: bad field\n", av[i]);
                }
                usage();
            }
        }
        else 
            files++;
    }
    if (!nprint) {
# ifndef ALLDEF
        usage();
# else
        for (j=0; fields[j].f_name; j++)
            nprint++, fields[j].f_print++;
# endif
    }

    if (from_stdin)
        files++;        /* We don't know how many files come from stdin. */

    if (files == 0) {   /* Stat all file descriptors. */
        if(do_readlink) return 0;
        for (i= 0; i<OPEN_MAX; i++) {
            err= fstat(i, &sbuf);
            if (err == -1 && errno == EBADF)
                continue;
            if (err == 0) {
                if (!first_file) fputc('\n', stdout);
                printf("fd %d:\n", i);
                printstat(&sbuf, nprint);
            }
            else {
                fprintf(stderr, "%s: fd %d: %s\n", arg0, i, strerror(errno));
                ret= 1;
            }
        }
        exit(ret);
    }
                
    for (i=1; i<ac; i++) {
        if (equal(av[i], "-")) {
            while (fgets(buf, sizeof(buf), stdin)) {
                char *p= strchr(buf, '\n');
                if (p) *p= 0;
#ifdef S_IFLNK
                if(do_readlink) {
                        char sbuf[300];
                        int n;
                        if((n=readlink(buf, sbuf, sizeof(sbuf)-1)) < 0) {
                                perror(buf);
                                continue;
                        }
                        sbuf[n] = '\0';
                        printf("%s: %s\n", buf, sbuf);
                        continue;
                }
#endif
                if (!sym) err= stat(av[i], &sbuf);
                if (sym || (err != 0 && errno == ENOENT)) {
                    err= lstat(av[i], &sbuf);
                }
                if (err == -1) {
                    fprintf(stderr, "%s: %s: %s\n",
                        arg0, av[i], strerror(errno));
                    ret= 1;
                }
                else {
                    if (!first_file) fputc('\n', stdout);
                    printf("%s:\n", buf);
                    printstat(&sbuf, nprint);
                }
            }
            continue;
        }
        if (av[i][0] == '-') {
            fd= strtoul(av[i]+1, &check, 10);
            if (check == av[i]+1 || *check != '\0') continue;
            if (fd >= INT_MAX) {
                err= -1;
                errno= EBADF;
            }
            else {
                err= fstat((int) fd, &sbuf);
            }
            if (err != -1) {
                if (!first_file) fputc('\n', stdout);
                if (files != 1) printf("fd %lu:\n", fd);
                printstat(&sbuf, nprint);
            }
            else {
                fprintf(stderr, "fd %lu: %s\n", fd, strerror(errno));
                ret= 1;
            }
            continue;
        }
        if(do_readlink) {
                char sbuf[300];
                int n;
                if((n=err=readlink(av[i], sbuf, sizeof(sbuf)-1)) < 0) {
                        perror(av[i]);
                        continue;
                }
                sbuf[n] = '\0';
                printf("%s: %s\n", av[i], sbuf);
                continue;
        }
        if (!sym) err= stat(av[i], &sbuf);
        if (sym || (err != 0 && errno == ENOENT)) err= lstat(av[i], &sbuf);
        if (err != -1) {
            if (!first_file) fputc('\n', stdout);
            if (files != 1) printf("%s:\n", av[i]);
            printstat(&sbuf, nprint);
        }
        else {
            fprintf(stderr, "%s: %s: %s\n", arg0, av[i], strerror(errno));
            ret= 1;
        }
    }
    exit(ret);
}

/*------------------------------------------------------------------30/Jan/87-*
 * printstat(file, nprint) - do the work
 *----------------------------------------------------------------larry mcvoy-*/
void printstat(struct stat *sbuf, int nprint)
{
    int      j;
    int      first_field= 1;

    for (j=0; fields[j].f_name; j++) {
        if (fields[j].f_print) {
            if (!first_field) fputc('\n', stdout);
            printit(sbuf, &fields[j], nprint);
            first_field= 0;
        }
    }
    fputc('\n', stdout);
    first_file= 0;
}

/*------------------------------------------------------------------30/Jan/87-*
 * printit(sb, f, n) - print the field
 *
 * Inputs    -> (struct stat*), (struct field*), (int)
 *
 * Results   -> Displays the field, with special handling of weird fields like
 *              mode and mtime.  The mode field is dumped in octal, followed
 *              by one or more of the S_IF<X> and/or S_I<X> values.
 *----------------------------------------------------------------larry mcvoy-*/
void printit(struct stat* sb, struct field* f, int n)
{
    if (n > 1)
        printf("%s: ", f->f_name);
    if (equal(f->f_name, "mode")) {
                /* This lot changed to my personal liking. (kjb) */
        char bit[11];

        printf("%07lo, ", (u_long) sb->st_mode);

        strcpy(bit, "----------");

        switch (sb->st_mode&S_IFMT) {
        case S_IFDIR:   bit[0]='d';     break;
# ifdef S_IFFIFO
        case S_IFFIFO:  bit[0]='p';     break;
# endif
        case S_IFCHR:   bit[0]='c';     break;
        case S_IFBLK:   bit[0]='b';     break;
# ifdef S_IFSOCK
        case S_IFSOCK:  bit[0]='S';     break;
# endif
# ifdef S_IFMPC
        case S_IFMPC:   bit[0]='C';     break;
# endif
# ifdef S_IFMPB
        case S_IFMPB:   bit[0]='B';     break;
# endif
# ifdef S_IFLNK
        case S_IFLNK:   bit[0]='l';     break;
# endif
        }
        rwx(sb->st_mode, bit+1);
        rwx(sb->st_mode<<3, bit+4);
        rwx(sb->st_mode<<6, bit+7);
        if (sb->st_mode&S_ISUID)        bit[3]='s';
        if (sb->st_mode&S_ISGID)        bit[6]='s';
        if (sb->st_mode&S_ISVTX)        bit[9]='t';
        printf("\"%s\"", bit);
    }
    /* times in human form, uppercase first letter */
    else if (equal("Ctime", f->f_name)) {
        printf("%.24s (%lu)", ctime(&sb->st_ctime), (u_long) sb->st_ctime);
        f[1].f_print= 0;
    }
    else if (equal("Mtime", f->f_name)) {
        printf("%.24s (%lu)", ctime(&sb->st_mtime), (u_long) sb->st_mtime);
        f[1].f_print= 0;
    }
    else if (equal("Atime", f->f_name)) {
        printf("%.24s (%lu)", ctime(&sb->st_atime), (u_long) sb->st_atime);
        f[1].f_print= 0;
    }
    else if (equal("ctime", f->f_name)) {
        printf("%lu", (u_long) sb->st_ctime);
    }
    else if (equal("mtime", f->f_name)) {
        printf("%lu", (u_long) sb->st_mtime);
    }
    else if (equal("atime", f->f_name)) {
        printf("%lu", (u_long) sb->st_atime);
    }
    else {
        switch (f->f_size) {
        case sizeof(char):
            printf("%d", * (u_char *) f->f_addr);
            break;
        case sizeof(short):
            printf("%u", (u_int) * (u_short *) f->f_addr);
            break;
#if INT_MAX != SHRT_MAX
        case sizeof(int):
            printf("%u", * (u_int *) f->f_addr);
            break;
#endif
#if LONG_MAX != INT_MAX && LONG_MAX != SHRT_MAX
        case sizeof(long):
            printf("%lu", * (u_long *) f->f_addr);
            break;
#endif
        default:
            fprintf(stderr, "\nProgram error: bad '%s' field size %d\n", 
                            f->f_name, f->f_size);
            break;
        }
    }
}

void rwx(mode_t mode, char *bit)
{
        if (mode&S_IREAD)       bit[0]='r';
        if (mode&S_IWRITE)      bit[1]='w';
        if (mode&S_IEXEC)       bit[2]='x';
}

void usage(void)
{
    fprintf(stderr,
        "Usage: %s [-] [-fd] [-all] [-s] [-field ...] [file1 ...]\n", 
        arg0);
    exit(1);
}

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