You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: hexdump_xxd.rs
    path of file: ./repos/rustybox/util_linux
    
    the code of the file until where you have to start completion: use crate::libbb::xfuncs_printf::xmalloc;
use crate::librb::smallint;
use libc;
use libc::free;
use libc::off_t;
use libc::sprintf;
extern "C" {

  #[no_mangle]
  static mut optind: libc::c_int;

  #[no_mangle]
  fn stpcpy(_: *mut libc::c_char, _: *const libc::c_char) -> *mut libc::c_char;

}

/* %_A */
/* rep count set, not default */
/* print offset */
/* blank pad */
/* %_c */
/* %c */
/* %[EefGf] */
/* %[di] */
/* %_p */
/* %s */
/* %_u */
/* %[ouXx] */
/* no conversions */

pub type dump_vflag_t = libc::c_uint;
// pub const WAIT: dump_vflag_t = 3;
// pub const FIRST: dump_vflag_t = 2;
// pub const DUP: dump_vflag_t = 1;
pub const ALL: dump_vflag_t = 0;

#[repr(C)]
#[derive(Copy, Clone)]
pub struct PR {
  pub nextpr: *mut PR,
  pub flags: libc::c_uint,
  pub bcnt: libc::c_int,
  pub cchar: *mut libc::c_char,
  pub fmt: *mut libc::c_char,
  pub nospace: *mut libc::c_char,
}

#[repr(C)]
#[derive(Copy, Clone)]
pub struct FU {
  pub nextfu: *mut FU,
  pub nextpr: *mut PR,
  pub flags: libc::c_uint,
  pub reps: libc::c_int,
  pub bcnt: libc::c_int,
  pub fmt: *mut libc::c_char,
}

#[repr(C)]
#[derive(Copy, Clone)]
pub struct FS {
  pub nextfs: *mut FS,
  pub nextfu: *mut FU,
  pub bcnt: libc::c_int,
}

use crate::libbb::dump::dumper_t;

/*
 * xxd implementation for busybox
 *
 * Copyright (c) 2017 Denys Vlasenko <vda.linux@gmail.com>
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */
//config:config XXD
//config:	bool "xxd (8.9 kb)"
//config:	default y
//config:	help
//config:	The xxd utility is used to display binary data in a readable
//config:	way that is comparable to the output from mo
    
pub unsafe fn xxd_main(mut _argc: libc::c_int, mut argv: *mut *mut libc::c_char) -> libc::c_int {
  let mut buf: [libc::c_char; 80] = [0; 80];
  let mut dumper: *mut dumper_t = std::ptr::null_mut();
  let mut opt_l: *mut libc::c_char = std::ptr::null_mut::<libc::c_char>();
  let mut opt_s: *mut libc::c_char = std::ptr::null_mut::<libc::c_char>();
  let mut bytes: libc::c_uint = 2i32 as libc::c_uint;
  let mut cols: libc::c_uint = 0 as libc::c_uint;
  let mut opt: libc::c_uint = 0;
  dumper = crate::libbb::dump::alloc_dumper();
  opt = crate::libbb::getopt32::getopt32(
    argv,
    b"^l:s:apg:+c:+\x00?1\x00" as *const u8 as *const libc::c_char,
    &mut opt_l as *mut *mut libc::c_char,
    &mut opt_s as *mut *mut libc::c_char,
    &mut bytes as *mut libc::c_uint,
    &mut cols as *mut libc::c_uint,
  );
  argv = argv.offset(optind as isize);
  (*dumper).dump_vflag = ALL as libc::c_int as smallint;
  //	if (opt & OPT_a)
  //		dumper->dump_vflag = SKIPNUL; ..does not exist
  if opt & (1i32 << 0) as libc::c_uint != 0 {
    (*dumper).dump_length = crate::libbb::xatonum::xstrtou_range(
      opt_l,
      0,
      0 as libc::c_uint,
      2147483647i32 as libc::c_uint,
    ) as libc::c_int
  }
  if opt & (1i32 << 1i32) as libc::c_uint != 0 {
    (*dumper).dump_skip = crate::libbb::xatonum::xstrtoull_range(
      opt_s,
      0,
      0 as libc::c_ulonglong,
      !((1i32 as off_t)
        << (::std::mem::size_of::<off_t>() as libc::c_ulong)
          .wrapping_mul(8i32 as libc::c_ulong)
          .wrapping_sub(1i32 as libc::c_ulong)) as libc::c_ulonglong,
    ) as off_t
    //BUGGY for /proc/version (unseekable?)
  }
  if opt & (1i32 << 3i32) as libc::c_uint != 0 {
    if cols == 0 as libc::c_uint {
      cols = 30i32 as libc::c_uint
    }
    bytes = cols
  /* -p ignores -gN */
  } else {
    if cols == 0 as libc::c_uint {
      cols = 16i32 as libc::c_uint
    }
    crate::libbb::dump::bb_dump_add(
      dumper,
      b"\"%08.8_ax: \"\x00" as *const u8 as *const libc::c_char,
    );
    // "address: "
  } // cols * "xx"
  if bytes < 1i32 as libc::c_uint || bytes >= cols {
    sprintf(
      buf.as_mut_ptr(),
      b"%u/1 \"%%02x\"\x00" as *const u8 as *const libc::c_char,
      cols,
    ); // cols * "xx "
    crate::libbb::dump::bb_dump_add(dumper, buf.as_mut_ptr());
  } else if bytes == 1i32 as libc::c_uint {
    sprintf(
      buf.as_mut_ptr(),
      b"%u/1 \"%%02x \"\x00" as *const u8 as *const libc::c_char,
      cols,
    );
    crate::libbb::dump::bb_dump_add(dumper, buf.as_mut_ptr());
  } else {
    /* Format "print byte" with and without trailing space */
    let mut i: libc::c_uint = 0;
    let mut bigbuf: *mut libc::c_char = xmalloc(
      (cols as libc::c_ulong).wrapping_mul(
        (::std::mem::size_of::<[libc::c_char; 11]>() as libc::c_ulong)
          .wrapping_sub(1i32 as libc::c_ulong),
      ),
    ) as *mut libc::c_char;
    let mut p: *mut libc::c_char = bigbuf;
    i = 1i32 as libc::c_uint;
    while i <= cols {
      if i == cols || i.wrapping_rem(bytes) != 0 {
        p = stpcpy(p, b"/1 \"%02x\"\x00" as *const u8 as *const libc::c_char)
      } else {
        p = stpcpy(p, b"/1 \"%02x \"\x00" as *const u8 as *const libc::c_char)
      }
      i = i.wrapping_add(1)
    }
    // for -g3, this results in B B BS B B BS... B = "xxxxxx xxxxxx .....xx"
    // todo: can be more clever and use
    // one 'bytes-1/1 "%02x"' format instead of many "B B B..." formats
    //bb_error_msg("ADDED:'%s'", bigbuf);
    crate::libbb::dump::bb_dump_add(dumper, bigbuf); // "  ASCII\n"
    free(bigbuf as *mut libc::c_void);
  }
  if opt & (1i32 << 3i32) as libc::c_uint == 0 {
    sprintf(
      buf.as_mut_ptr(),
      b"\"  \"%u/1 \"%%_p\"\"\n\"\x00" as *const u8 as *const libc::c_char,
      cols,
    );
    crate::libbb::dump::bb_dump_add(dumper, buf.as_mut_ptr());
  } else {
    crate::libbb::dump::bb_dump_add(dumper, b"\"\n\"\x00" as *const u8 as *const libc::c_char);
  }
  return crate::libbb::dump::bb_dump_dump(dumper, argv);
}