od: improve/extend --help text

Cargo.lock

@@ -666,7 +666,6 @@ dependencies = [
  "byteorder 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "getopts 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "unindent 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "uucore 0.0.1",
 ]
 

src/od/Cargo.toml

@@ -10,7 +10,6 @@ path = "od.rs"
 [dependencies]
 getopts = "*"
 libc = "*"
-unindent = "*"
 byteorder = "*"
 uucore = { path="../uucore" }
 

src/od/od.rs

@@ -10,7 +10,6 @@
  */
 
 extern crate getopts;
-extern crate unindent;
 extern crate byteorder;
 
 #[macro_use]
@@ -32,7 +31,6 @@ mod mockstream;
 
 use std::cmp;
 use std::io::Write;
-use unindent::*;
 use byteorder_io::*;
 use multifilereader::*;
 use partialreader::*;
@@ -50,6 +48,50 @@ const PEEK_BUFFER_SIZE: usize = 4; // utf-8 can be 4 bytes
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 enum Radix { Decimal, Hexadecimal, Octal, NoPrefix }
 
+static USAGE: &'static str =
+r#"Usage:
+    od [OPTION]... [--] [FILENAME]...
+    od [-abcdDefFhHiIlLoOsxX] [FILENAME] [[+][0x]OFFSET[.][b]]
+    od --traditional [OPTION]... [FILENAME] [[+][0x]OFFSET[.][b] [[+][0x]LABEL[.][b]]]
+
+Displays data in various human-readable formats. If multiple formats are
+specified, the output will contain all formats in the order they appear on the
+commandline. Each format will be printed on a new line. Only the line
+containing the first format will be prefixed with the offset.
+
+If no filename is specified, or it is "-", stdin will be used. After a "--", no
+more options will be recognised. This allows for filenames starting with a "-".
+
+If a filename is a valid number which can be used as an offset in the second
+form, you can force it to be recognised as a filename if you include an option
+like "-j0", which is only valid in the first form.
+
+RADIX is one of o,d,x,n for octal, decimal, hexadecimal or none.
+
+BYTES is decimal by default, octal if prefixed with a "0", or hexadecimal if
+prefixed with "0x". The suffixes b, KB, K, MB, M, GB, G, will multiply the
+number with 512, 1000, 1024, 1000^2, 1024^2, 1000^3, 1024^3, 1000^2, 1024^2.
+
+OFFSET and LABEL are octal by default, hexadecimal if prefixed with "0x" or
+decimal if a "." suffix is added. The "b" suffix will multiply with 512.
+
+TYPE contains one or more format specifications consisting of:
+    a       for printable 7-bits ASCII
+    c       for utf-8 characters or octal for undefined characters
+    d[SIZE] for signed decimal
+    f[SIZE] for floating point
+    o[SIZE] for octal
+    u[SIZE] for unsigned decimal
+    x[SIZE] for hexadecimal
+SIZE is the number of bytes which can be the number 1, 2, 4, 8 or 16,
+    or C, I, S, L for 1, 2, 4, 8 bytes for integer types,
+    or F, D, L for 4, 8, 16 bytes for floating point.
+Any type specification can have a "z" suffic, which will add a ASCII dump at
+    the end of the line.
+
+If an error occurred, a diagnostic message will be printed to stderr, and the
+exitcode will be non-zero."#;
+
 pub fn uumain(args: Vec<String>) -> i32 {
     let mut opts = getopts::Options::new();
 
@@ -106,12 +148,7 @@ pub fn uumain(args: Vec<String>) -> i32 {
     };
 
     if matches.opt_present("h") {
-        let msg = unindent(&format!("
+        println!("{}", opts.usage(&USAGE));
-                Usage:
-                    {0} [OPTION]... [FILENAME]...
-
-                Displays data in various human-readable formats.", executable!()));
-        println!("{}", opts.usage(&msg));
         return 0;
     }
     if matches.opt_present("version") {