If integer is greater than the length of str, returns a new String of length integer with str right justified and padded with padstr; otherwise, returns str.
"hello".rjust(4) #=> "hello" "hello".rjust(20) #=> " hello" "hello".rjust(20, '1234') #=> "123412341234123hello"
Returns a copy of str with the characters in from_str replaced by the corresponding characters in to_str. If to_str is shorter than from_str, it is padded with its last character in order to maintain the correspondence.
"hello".tr('el', 'ip') #=> "hippo" "hello".tr('aeiou', '*') #=> "h*ll*" "hello".tr('aeiou', 'AA*') #=> "hAll*"
Both strings may use the c1-c2 notation to denote ranges of characters, and from_str may start with a ^, which denotes all characters except those listed.
"hello".tr('a-y', 'b-z') #=> "ifmmp" "hello".tr('^aeiou', '*') #=> "*e**o"
The backslash character \ can be used to escape ^ or - and is otherwise ignored unless it appears at the end of a range or the end of the from_str or to_str:
"hello^world".tr("\\^aeiou", "*") #=> "h*ll**w*rld" "hello-world".tr("a\\-eo", "*") #=> "h*ll**w*rld" "hello\r\nworld".tr("\r", "") #=> "hello\nworld" "hello\r\nworld".tr("\\r", "") #=> "hello\r\nwold" "hello\r\nworld".tr("\\\r", "") #=> "hello\nworld" "X['\\b']".tr("X\\", "") #=> "['b']" "X['\\b']".tr("X-\\]", "") #=> "'b'"
Translates str in place, using the same rules as String#tr. Returns str, or nil if no changes were made.
Returns a string containing the IP address representation in canonical form.
Convert self to ISO-2022-JP
Convert self to EUC-JP
Convert self to Shift_JIS
Convert self to UTF-8
Convert self to UTF-16
Convert self to UTF-32
Convert self to locale encoding
Returns whether self‘s encoding is EUC-JP or not.
Returns whether self‘s encoding is Shift_JIS or not.
Returns whether self‘s encoding is ISO-2022-JP or not.
Returns whether self‘s encoding is UTF-8 or not.
Scans the current string. If a block is given, it functions exactly like block_scanf.
arr = "123 456".scanf("%d%d") # => [123, 456] require 'pp' "this 123 read that 456 other".scanf("%s%d%s") {|m| pp m} # ["this", 123, "read"] # ["that", 456, "other"] # => [["this", 123, "read"], ["that", 456, "other"]]
See Scanf for details on creating a format string.
You will need to require ‘scanf’ to use String#scanf
Splits str into an array of tokens in the same way the UNIX Bourne shell does.
See Shellwords.shellsplit for details.
Escapes str so that it can be safely used in a Bourne shell command line.
See Shellwords.shellescape for details.
Decodes str (which may contain binary data) according to the format string, returning an array of each value extracted. The format string consists of a sequence of single-character directives, summarized in the table at the end of this entry. Each directive may be followed by a number, indicating the number of times to repeat with this directive. An asterisk (“*”) will use up all remaining elements. The directives sSiIlL may each be followed by an underscore (“_”) or exclamation mark (“!”) to use the underlying platform’s native size for the specified type; otherwise, it uses a platform-independent consistent size. Spaces are ignored in the format string. See also String#unpack1, Array#pack.
"abc \0\0abc \0\0".unpack('A6Z6') #=> ["abc", "abc "] "abc \0\0".unpack('a3a3') #=> ["abc", " \000\000"] "abc \0abc \0".unpack('Z*Z*') #=> ["abc ", "abc "] "aa".unpack('b8B8') #=> ["10000110", "01100001"] "aaa".unpack('h2H2c') #=> ["16", "61", 97] "\xfe\xff\xfe\xff".unpack('sS') #=> [-2, 65534] "now=20is".unpack('M*') #=> ["now is"] "whole".unpack('xax2aX2aX1aX2a') #=> ["h", "e", "l", "l", "o"]
This table summarizes the various formats and the Ruby classes returned by each.
Integer | |
Directive | Returns | Meaning
------------------------------------------------------------------
C | Integer | 8-bit unsigned (unsigned char)
S | Integer | 16-bit unsigned, native endian (uint16_t)
L | Integer | 32-bit unsigned, native endian (uint32_t)
Q | Integer | 64-bit unsigned, native endian (uint64_t)
J | Integer | pointer width unsigned, native endian (uintptr_t)
| |
c | Integer | 8-bit signed (signed char)
s | Integer | 16-bit signed, native endian (int16_t)
l | Integer | 32-bit signed, native endian (int32_t)
q | Integer | 64-bit signed, native endian (int64_t)
j | Integer | pointer width signed, native endian (intptr_t)
| |
S_ S! | Integer | unsigned short, native endian
I I_ I! | Integer | unsigned int, native endian
L_ L! | Integer | unsigned long, native endian
Q_ Q! | Integer | unsigned long long, native endian (ArgumentError
| | if the platform has no long long type.)
J! | Integer | uintptr_t, native endian (same with J)
| |
s_ s! | Integer | signed short, native endian
i i_ i! | Integer | signed int, native endian
l_ l! | Integer | signed long, native endian
q_ q! | Integer | signed long long, native endian (ArgumentError
| | if the platform has no long long type.)
j! | Integer | intptr_t, native endian (same with j)
| |
S> s> S!> s!> | Integer | same as the directives without ">" except
L> l> L!> l!> | | big endian
I!> i!> | |
Q> q> Q!> q!> | | "S>" is same as "n"
J> j> J!> j!> | | "L>" is same as "N"
| |
S< s< S!< s!< | Integer | same as the directives without "<" except
L< l< L!< l!< | | little endian
I!< i!< | |
Q< q< Q!< q!< | | "S<" is same as "v"
J< j< J!< j!< | | "L<" is same as "V"
| |
n | Integer | 16-bit unsigned, network (big-endian) byte order
N | Integer | 32-bit unsigned, network (big-endian) byte order
v | Integer | 16-bit unsigned, VAX (little-endian) byte order
V | Integer | 32-bit unsigned, VAX (little-endian) byte order
| |
U | Integer | UTF-8 character
w | Integer | BER-compressed integer (see Array.pack)
Float | |
Directive | Returns | Meaning
-----------------------------------------------------------------
D d | Float | double-precision, native format
F f | Float | single-precision, native format
E | Float | double-precision, little-endian byte order
e | Float | single-precision, little-endian byte order
G | Float | double-precision, network (big-endian) byte order
g | Float | single-precision, network (big-endian) byte order
String | |
Directive | Returns | Meaning
-----------------------------------------------------------------
A | String | arbitrary binary string (remove trailing nulls and ASCII spaces)
a | String | arbitrary binary string
Z | String | null-terminated string
B | String | bit string (MSB first)
b | String | bit string (LSB first)
H | String | hex string (high nibble first)
h | String | hex string (low nibble first)
u | String | UU-encoded string
M | String | quoted-printable, MIME encoding (see RFC2045)
m | String | base64 encoded string (RFC 2045) (default)
| | base64 encoded string (RFC 4648) if followed by 0
P | String | pointer to a structure (fixed-length string)
p | String | pointer to a null-terminated string
Misc. | |
Directive | Returns | Meaning
-----------------------------------------------------------------
@ | --- | skip to the offset given by the length argument
X | --- | skip backward one byte
x | --- | skip forward one byte
HISTORY
J, J! j, and j! are available since Ruby 2.3.
Q_, Q!, q_, and q! are available since Ruby 2.1.
I!<, i!<, I!>, and i!> are available since Ruby 1.9.3.
Decodes str (which may contain binary data) according to the format string, returning the first value extracted. See also String#unpack, Array#pack.
Returns a new string object containing a copy of str.
The optional encoding keyword argument specifies the encoding of the new string. If not specified, the encoding of str is used (or ASCII-8BIT, if str is not specified).
The optional capacity keyword argument specifies the size of the internal buffer. This may improve performance, when the string will be concatenated many times (causing many realloc calls).