In Files

  • io.c

ARGF

ARGF is a stream designed for use in scripts that process files given as command-line arguments, or passed in via STDIN.

The arguments passed to your script are stored in the ARGV Array, one argument per element. ARGF assumes that any arguments that aren't filenames have been removed from ARGV. For example:

$ ruby argf.rb --verbose file1 file2

ARGV  #=> ["--verbose", "file1", "file2"]
option = ARGV.shift #=> "--verbose"
ARGV  #=> ["file1", "file2"]

You can now use ARGF to work with a concatenation of each of these named files. For instance, ARGF.read will return the contents of file1 followed by the contents of file2.

After a file in ARGV has been read, ARGF removes it from the Array. Thus, after all files have been read ARGV will be empty.

You can manipulate ARGV yourself to control what ARGF operates on. If you remove a file from ARGV, it is ignored by ARGF; if you add files to ARGV, they are treated as if they were named on the command line. For example:

ARGV.replace ["file1"]
ARGF.readlines # Returns the contents of file1 as an Array
ARGV           #=> []
ARGV.replace ["file2", "file3"]
ARGF.read      # Returns the contents of file2 and file3

If ARGV is empty, ARGF acts as if it contained STDIN, i.e. the data piped to your script. For example:

$ echo "glark" | ruby -e 'p ARGF.read'
"glark\n"

Public Instance Methods

argv → ARGV click to toggle source

Returns the ARGV array, which contains the arguments passed to your script, one per element.

For example:

$ ruby argf.rb -v glark.txt

ARGF.argv   #=> ["-v", "glark.txt"]
 
               static VALUE
argf_argv(VALUE argf)
{
    return ARGF.argv;
}
            
binmode → ARGF click to toggle source

Puts ARGF into binary mode. Once a stream is in binary mode, it cannot be reset to non-binary mode. This option has the following effects:

  • Newline conversion is disabled.

  • Encoding conversion is disabled.

  • Content is treated as ASCII-8BIT.

 
               static VALUE
argf_binmode_m(VALUE argf)
{
    ARGF.binmode = 1;
    next_argv();
    ARGF_FORWARD(0, 0);
    rb_io_ascii8bit_binmode(ARGF.current_file);
    return argf;
}
            
binmode? → true or false click to toggle source
Returns true if +ARGF+ is being read in binary mode; false otherwise. (To
enable binary mode use +ARGF.binmode+.

For example:

ARGF.binmode?  #=> false
ARGF.binmode
ARGF.binmode?  #=> true
 
               static VALUE
argf_binmode_p(VALUE argf)
{
    return ARGF.binmode ? Qtrue : Qfalse;
}
            
bytes {|byte| block } → ARGF click to toggle source
bytes → an_enumerator
Iterates over each byte of each file in +ARGV+.
A byte is returned as a +Fixnum+ in the range 0..255.

This method allows you to treat the files supplied on the command line as
a single file consisting of the concatenation of each named file. After
the last byte of the first file has been returned, the first byte of the
second file is returned. The +ARGF.filename+ method can be used to
determine the filename of the current byte.

If no block is given, an enumerator is returned instead.

For example:

ARGF.bytes.to_a  #=> [35, 32, ... 95, 10]
 
               static VALUE
argf_each_byte(VALUE argf)
{
    RETURN_ENUMERATOR(argf, 0, 0);
    for (;;) {
        if (!next_argv()) return argf;
        rb_block_call(ARGF.current_file, rb_intern("each_byte"), 0, 0, 0, 0);
        ARGF.next_p = 1;
    }
}
            
chars {|char| block } → ARGF click to toggle source
chars → an_enumerator

Iterates over each character of each file in ARGF.

This method allows you to treat the files supplied on the command line as a single file consisting of the concatenation of each named file. After the last character of the first file has been returned, the first character of the second file is returned. The ARGF.filename method can be used to determine the name of the file in which the current character appears.

If no block is given, an enumerator is returned instead.

 
               static VALUE
argf_each_char(VALUE argf)
{
    RETURN_ENUMERATOR(argf, 0, 0);
    for (;;) {
        if (!next_argv()) return argf;
        rb_block_call(ARGF.current_file, rb_intern("each_char"), 0, 0, 0, 0);
        ARGF.next_p = 1;
    }
}
            
close → ARGF click to toggle source
Closes the current file and skips to the next in the stream. Trying to
close a file that has already been closed causes an +IOError+ to be
raised.

For example:

$ ruby argf.rb foo bar

ARGF.filename  #=> "foo"
ARGF.close
ARGF.filename  #=> "bar"
ARGF.close
ARGF.close     #=> closed stream (IOError)
 
               static VALUE
argf_close_m(VALUE argf)
{
    next_argv();
    argf_close(ARGF.current_file);
    if (ARGF.next_p != -1) {
        ARGF.next_p = 1;
    }
    ARGF.lineno = 0;
    return argf;
}
            
closed? → true or false click to toggle source

Returns true if the current file has been closed; false otherwise. Use ARGF.close to actually close the current file.

 
               static VALUE
argf_closed(VALUE argf)
{
    next_argv();
    ARGF_FORWARD(0, 0);
    return rb_io_closed(ARGF.current_file);
}
            
each(sep=$/) {|line| block } → ARGF click to toggle source
each(sep=$/,limit) {|line| block } → ARGF
each(...) → an_enumerator
each_line(sep=$/) {|line| block } → ARGF
each_line(sep=$/,limit) {|line| block } → ARGF
each_line(...) → an_enumerator

Returns an enumerator which iterates over each line (separated by sep, which defaults to your platform’s newline character) of each file in ARGV. If a block is supplied, each line in turn will be yielded to the block, otherwise an enumerator is returned. The optional limit argument is a Fixnum specifying the maximum length of each line; longer lines will be split according to this limit.

This method allows you to treat the files supplied on the command line as a single file consisting of the concatenation of each named file. After the last line of the first file has been returned, the first line of the second file is returned. The ARGF.filename and ARGF.lineno methods can be used to determine the filename and line number, respectively, of the current line.

For example, the following code prints out each line of each named file prefixed with its line number, displaying the filename once per file:

ARGF.lines do |line|
  puts ARGF.filename if ARGF.lineno == 1
  puts "#{ARGF.lineno}: #{line}"
end
 
               static VALUE
argf_each_line(int argc, VALUE *argv, VALUE argf)
{
    RETURN_ENUMERATOR(argf, argc, argv);
    for (;;) {
        if (!next_argv()) return argf;
        rb_block_call(ARGF.current_file, rb_intern("each_line"), argc, argv, 0, 0);
        ARGF.next_p = 1;
    }
}
            
each_byte {|byte| block } → ARGF click to toggle source
each_byte → an_enumerator
Iterates over each byte of each file in +ARGV+.
A byte is returned as a +Fixnum+ in the range 0..255.

This method allows you to treat the files supplied on the command line as
a single file consisting of the concatenation of each named file. After
the last byte of the first file has been returned, the first byte of the
second file is returned. The +ARGF.filename+ method can be used to
determine the filename of the current byte.

If no block is given, an enumerator is returned instead.

For example:

ARGF.bytes.to_a  #=> [35, 32, ... 95, 10]
 
               static VALUE
argf_each_byte(VALUE argf)
{
    RETURN_ENUMERATOR(argf, 0, 0);
    for (;;) {
        if (!next_argv()) return argf;
        rb_block_call(ARGF.current_file, rb_intern("each_byte"), 0, 0, 0, 0);
        ARGF.next_p = 1;
    }
}
            
each_char {|char| block } → ARGF click to toggle source
each_char → an_enumerator

Iterates over each character of each file in ARGF.

This method allows you to treat the files supplied on the command line as a single file consisting of the concatenation of each named file. After the last character of the first file has been returned, the first character of the second file is returned. The ARGF.filename method can be used to determine the name of the file in which the current character appears.

If no block is given, an enumerator is returned instead.

 
               static VALUE
argf_each_char(VALUE argf)
{
    RETURN_ENUMERATOR(argf, 0, 0);
    for (;;) {
        if (!next_argv()) return argf;
        rb_block_call(ARGF.current_file, rb_intern("each_char"), 0, 0, 0, 0);
        ARGF.next_p = 1;
    }
}
            
each_line(sep=$/) {|line| block } → ARGF click to toggle source
each_line(sep=$/,limit) {|line| block } → ARGF
each_line(...) → an_enumerator

Returns an enumerator which iterates over each line (separated by sep, which defaults to your platform’s newline character) of each file in ARGV. If a block is supplied, each line in turn will be yielded to the block, otherwise an enumerator is returned. The optional limit argument is a Fixnum specifying the maximum length of each line; longer lines will be split according to this limit.

This method allows you to treat the files supplied on the command line as a single file consisting of the concatenation of each named file. After the last line of the first file has been returned, the first line of the second file is returned. The ARGF.filename and ARGF.lineno methods can be used to determine the filename and line number, respectively, of the current line.

For example, the following code prints out each line of each named file prefixed with its line number, displaying the filename once per file:

ARGF.lines do |line|
  puts ARGF.filename if ARGF.lineno == 1
  puts "#{ARGF.lineno}: #{line}"
end
 
               static VALUE
argf_each_line(int argc, VALUE *argv, VALUE argf)
{
    RETURN_ENUMERATOR(argf, argc, argv);
    for (;;) {
        if (!next_argv()) return argf;
        rb_block_call(ARGF.current_file, rb_intern("each_line"), argc, argv, 0, 0);
        ARGF.next_p = 1;
    }
}
            
eof? → true or false click to toggle source
eof → true or false

Returns true if the current file in ARGF is at end of file, i.e. it has no data to read. The stream must be opened for reading or an IOError will be raised.

$ echo "eof" | ruby argf.rb

ARGF.eof?                 #=> false
3.times { ARGF.readchar }
ARGF.eof?                 #=> false
ARGF.readchar             #=> "\n"
ARGF.eof?                 #=> true
 
               static VALUE
argf_eof(VALUE argf)
{
    next_argv();
    if (RTEST(ARGF.current_file)) {
        if (ARGF.init_p == 0) return Qtrue;
        next_argv();
        ARGF_FORWARD(0, 0);
        if (rb_io_eof(ARGF.current_file)) {
            return Qtrue;
        }
    }
    return Qfalse;
}
            
eof? → true or false click to toggle source

Returns true if the current file in ARGF is at end of file, i.e. it has no data to read. The stream must be opened for reading or an IOError will be raised.

$ echo "eof" | ruby argf.rb

ARGF.eof?                 #=> false
3.times { ARGF.readchar }
ARGF.eof?                 #=> false
ARGF.readchar             #=> "\n"
ARGF.eof?                 #=> true
 
               static VALUE
argf_eof(VALUE argf)
{
    next_argv();
    if (RTEST(ARGF.current_file)) {
        if (ARGF.init_p == 0) return Qtrue;
        next_argv();
        ARGF_FORWARD(0, 0);
        if (rb_io_eof(ARGF.current_file)) {
            return Qtrue;
        }
    }
    return Qfalse;
}
            
external_encoding → encoding click to toggle source
Returns the external encoding for files read from +ARGF+ as an +Encoding+
object. The external encoding is the encoding of the text as stored in a
file. Contrast with +ARGF.internal_encoding+, which is the encoding used
to represent this text within Ruby.

To set the external encoding use +ARGF.set_encoding+.

For example:

ARGF.external_encoding  #=>  #<Encoding:UTF-8>
 
               static VALUE
argf_external_encoding(VALUE argf)
{
    if (!RTEST(ARGF.current_file)) {
        return rb_enc_from_encoding(rb_default_external_encoding());
    }
    return rb_io_external_encoding(rb_io_check_io(ARGF.current_file));
}
            
file → IO or File object click to toggle source

Returns the current file as an IO or File object. #<IO:<STDIN>> is returned when the current file is STDIN.

For example:

$ echo "foo" > foo
$ echo "bar" > bar

$ ruby argf.rb foo bar

ARGF.file      #=> #<File:foo>
ARGF.read(5)   #=> "foo\nb"
ARGF.file      #=> #<File:bar>
 
               static VALUE
argf_file(VALUE argf)
{
    next_argv();
    return ARGF.current_file;
}
            
filename → String click to toggle source

Returns the current filename. “-” is returned when the current file is STDIN.

For example:

$ echo "foo" > foo
$ echo "bar" > bar
$ echo "glark" > glark

$ ruby argf.rb foo bar glark

ARGF.filename  #=> "foo"
ARGF.read(5)   #=> "foo\nb"
ARGF.filename  #=> "bar"
ARGF.skip
ARGF.filename  #=> "glark"
 
               static VALUE
argf_filename(VALUE argf)
{
    next_argv();
    return ARGF.filename;
}
            
fileno → fixnum click to toggle source

Returns an integer representing the numeric file descriptor for the current file. Raises an ArgumentError if there isn’t a current file.

ARGF.fileno    #=> 3
 
               static VALUE
argf_fileno(VALUE argf)
{
    if (!next_argv()) {
        rb_raise(rb_eArgError, "no stream");
    }
    ARGF_FORWARD(0, 0);
    return rb_io_fileno(ARGF.current_file);
}
            
getbyte → Fixnum or nil click to toggle source

Gets the next 8-bit byte (0..255) from ARGF. Returns nil if called at the end of the stream.

For example:

$ echo "foo" > file
$ ruby argf.rb file

ARGF.getbyte #=> 102
ARGF.getbyte #=> 111
ARGF.getbyte #=> 111
ARGF.getbyte #=> 10
ARGF.getbyte #=> nil
 
               static VALUE
argf_getbyte(VALUE argf)
{
    VALUE ch;

  retry:
    if (!next_argv()) return Qnil;
    if (TYPE(ARGF.current_file) != T_FILE) {
        ch = rb_funcall3(ARGF.current_file, rb_intern("getbyte"), 0, 0);
    }
    else {
        ch = rb_io_getbyte(ARGF.current_file);
    }
    if (NIL_P(ch) && ARGF.next_p != -1) {
        argf_close(ARGF.current_file);
        ARGF.next_p = 1;
        goto retry;
    }

    return ch;
}
            
getc → String or nil click to toggle source

Reads the next character from ARGF and returns it as a String. Returns nil at the end of the stream.

ARGF treats the files named on the command line as a single file created by concatenating their contents. After returning the last character of the first file, it returns the first character of the second file, and so on.

For example:

$ echo "foo" > file
$ ruby argf.rb file

ARGF.getc  #=> "f"
ARGF.getc  #=> "o"
ARGF.getc  #=> "o"
ARGF.getc  #=> "\n"
ARGF.getc  #=> nil
ARGF.getc  #=> nil
 
               static VALUE
argf_getc(VALUE argf)
{
    VALUE ch;

  retry:
    if (!next_argv()) return Qnil;
    if (ARGF_GENERIC_INPUT_P()) {
        ch = rb_funcall3(ARGF.current_file, rb_intern("getc"), 0, 0);
    }
    else {
        ch = rb_io_getc(ARGF.current_file);
    }
    if (NIL_P(ch) && ARGF.next_p != -1) {
        argf_close(ARGF.current_file);
        ARGF.next_p = 1;
        goto retry;
    }

    return ch;
}
            
gets(sep=$/) → string click to toggle source
gets(limit) → string
gets(sep, limit) → string

Returns the next line from the current file in ARGF.

By default lines are assumed to be separated by +$/+; to use a different character as a separator, supply it as a String for the sep argument.

The optional limit argument specifies how many characters of each line to return. By default all characters are returned.

 
               static VALUE
argf_gets(int argc, VALUE *argv, VALUE argf)
{
    VALUE line;

    line = argf_getline(argc, argv, argf);
    rb_lastline_set(line);

    return line;
}
            
inplace_mode → String click to toggle source

Returns the file extension appended to the names of modified files under inplace-edit mode. This value can be set using ARGF.inplace_mode= or passing the -i switch to the Ruby binary.

 
               static VALUE
argf_inplace_mode_get(VALUE argf)
{
    if (!ARGF.inplace) return Qnil;
    return rb_str_new2(ARGF.inplace);
}
            
inplace_mode = ext → ARGF click to toggle source
Sets the filename extension for inplace editing mode to the given String.
Each file being edited has this value appended to its filename. The
modified file is saved under this new name.

For example:

    $ ruby argf.rb file.txt

    ARGF.inplace_mode = '.bak'
    ARGF.lines do |line|
      print line.sub("foo","bar")
    end

Each line of file.txt has the first occurrence of “foo” replaced with “bar”, then the new line is written out to file.txt.bak.

 
               static VALUE
argf_inplace_mode_set(VALUE argf, VALUE val)
{
    if (rb_safe_level() >= 1 && OBJ_TAINTED(val))
        rb_insecure_operation();

    if (!RTEST(val)) {
        if (ARGF.inplace) free(ARGF.inplace);
        ARGF.inplace = 0;
    }
    else {
        StringValue(val);
        if (ARGF.inplace) free(ARGF.inplace);
        ARGF.inplace = 0;
        ARGF.inplace = strdup(RSTRING_PTR(val));
    }
    return argf;
}
            
internal_encoding → encoding click to toggle source

Returns the internal encoding for strings read from ARGF as an Encoding object.

If ARGF.set_encoding has been called with two encoding names, the second is returned. Otherwise, if Encoding.default_external has been set, that value is returned. Failing that, if a default external encoding was specified on the command-line, that value is used. If the encoding is unknown, nil is returned.

 
               static VALUE
argf_internal_encoding(VALUE argf)
{
    if (!RTEST(ARGF.current_file)) {
        return rb_enc_from_encoding(rb_default_external_encoding());
    }
    return rb_io_internal_encoding(rb_io_check_io(ARGF.current_file));
}
            
lineno → integer click to toggle source

Returns the current line number of ARGF as a whole. This value can be set manually with ARGF.lineno=.

For example:

ARGF.lineno   #=> 0
ARGF.readline #=> "This is line 1\n"
ARGF.lineno   #=> 1
 
               static VALUE
argf_lineno(VALUE argf)
{
    return INT2FIX(ARGF.lineno);
}
            
lineno = number → nil click to toggle source

Sets the line number of ARGF as a whole to the given Integer.

ARGF sets the line number automatically as you read data, so normally you will not need to set it explicitly. To access the current line number use ARGF.lineno.

For example:

ARGF.lineno      #=> 0
ARGF.readline    #=> "This is line 1\n"
ARGF.lineno      #=> 1
ARGF.lineno = 0  #=> nil
ARGF.lineno      #=> 0
 
               static VALUE
argf_set_lineno(VALUE argf, VALUE val)
{
    ARGF.lineno = NUM2INT(val);
    ARGF.last_lineno = ARGF.lineno;
    return Qnil;
}
            
lines(sep=$/) {|line| block } → ARGF click to toggle source
lines(sep=$/,limit) {|line| block } → ARGF
lines(...) → an_enumerator

Returns an enumerator which iterates over each line (separated by sep, which defaults to your platform’s newline character) of each file in ARGV. If a block is supplied, each line in turn will be yielded to the block, otherwise an enumerator is returned. The optional limit argument is a Fixnum specifying the maximum length of each line; longer lines will be split according to this limit.

This method allows you to treat the files supplied on the command line as a single file consisting of the concatenation of each named file. After the last line of the first file has been returned, the first line of the second file is returned. The ARGF.filename and ARGF.lineno methods can be used to determine the filename and line number, respectively, of the current line.

For example, the following code prints out each line of each named file prefixed with its line number, displaying the filename once per file:

ARGF.lines do |line|
  puts ARGF.filename if ARGF.lineno == 1
  puts "#{ARGF.lineno}: #{line}"
end
 
               static VALUE
argf_each_line(int argc, VALUE *argv, VALUE argf)
{
    RETURN_ENUMERATOR(argf, argc, argv);
    for (;;) {
        if (!next_argv()) return argf;
        rb_block_call(ARGF.current_file, rb_intern("each_line"), argc, argv, 0, 0);
        ARGF.next_p = 1;
    }
}
            
path → String click to toggle source

Returns the current filename. “-” is returned when the current file is STDIN.

For example:

$ echo "foo" > foo
$ echo "bar" > bar
$ echo "glark" > glark

$ ruby argf.rb foo bar glark

ARGF.filename  #=> "foo"
ARGF.read(5)   #=> "foo\nb"
ARGF.filename  #=> "bar"
ARGF.skip
ARGF.filename  #=> "glark"
 
               static VALUE
argf_filename(VALUE argf)
{
    next_argv();
    return ARGF.filename;
}
            
pos → Integer click to toggle source

Returns the current offset (in bytes) of the current file in ARGF.

ARGF.pos    #=> 0
ARGF.gets   #=> "This is line one\n"
ARGF.pos    #=> 17
 
               static VALUE
argf_tell(VALUE argf)
{
    if (!next_argv()) {
        rb_raise(rb_eArgError, "no stream to tell");
    }
    ARGF_FORWARD(0, 0);
    return rb_io_tell(ARGF.current_file);
}
            
pos = position → Integer click to toggle source

Seeks to the position given by position (in bytes) in ARGF.

For example:

ARGF.pos = 17
ARGF.gets   #=> "This is line two\n"
 
               static VALUE
argf_set_pos(VALUE argf, VALUE offset)
{
    if (!next_argv()) {
        rb_raise(rb_eArgError, "no stream to set position");
    }
    ARGF_FORWARD(1, &offset);
    return rb_io_set_pos(ARGF.current_file, offset);
}
            
read([length [, buffer]]) → string, buffer, or nil click to toggle source
Reads _length_ bytes from ARGF. The files named on the command line
are concatenated and treated as a single file by this method, so when
called without arguments the contents of this pseudo file are returned in
their entirety.

_length_ must be a non-negative integer or nil. If it is a positive
integer, +read+ tries to read at most _length_ bytes. It returns nil
if an EOF was encountered before anything could be read. Fewer than
_length_ bytes may be returned if an EOF is encountered during the read.

If _length_ is omitted or is _nil_, it reads until EOF. A String is
returned even if EOF is encountered before any data is read.

If _length_ is zero, it returns _""_.

If the optional _buffer_ argument is present, it must reference a String,
which will receive the data.

For example:

   $ echo "small" > small.txt
   $ echo "large" > large.txt
   $ ./glark.rb small.txt large.txt

   ARGF.read      #=> "small\nlarge"
   ARGF.read(200) #=> "small\nlarge"
   ARGF.read(2)   #=> "sm"
   ARGF.read(0)   #=> ""

Note that this method behaves like fread() function in C.  If you need the
behavior like read(2) system call, consider +ARGF.readpartial+.
 
               static VALUE
argf_read(int argc, VALUE *argv, VALUE argf)
{
    VALUE tmp, str, length;
    long len = 0;

    rb_scan_args(argc, argv, "02", &length, &str);
    if (!NIL_P(length)) {
        len = NUM2LONG(argv[0]);
    }
    if (!NIL_P(str)) {
        StringValue(str);
        rb_str_resize(str,0);
        argv[1] = Qnil;
    }

  retry:
    if (!next_argv()) {
        return str;
    }
    if (ARGF_GENERIC_INPUT_P()) {
        tmp = argf_forward(argc, argv, argf);
    }
    else {
        tmp = io_read(argc, argv, ARGF.current_file);
    }
    if (NIL_P(str)) str = tmp;
    else if (!NIL_P(tmp)) rb_str_append(str, tmp);
    if (NIL_P(tmp) || NIL_P(length)) {
        if (ARGF.next_p != -1) {
            argf_close(ARGF.current_file);
            ARGF.next_p = 1;
            goto retry;
        }
    }
    else if (argc >= 1) {
        if (RSTRING_LEN(str) < len) {
            len -= RSTRING_LEN(str);
            argv[0] = INT2NUM(len);
            goto retry;
        }
    }
    return str;
}
            
readbyte → Fixnum click to toggle source

Reads the next 8-bit byte from ARGF and returns it as a Fixnum. Raises an EOFError after the last byte of the last file has been read.

For example:

$ echo "foo" > file
$ ruby argf.rb file

ARGF.readbyte  #=> 102
ARGF.readbyte  #=> 111
ARGF.readbyte  #=> 111
ARGF.readbyte  #=> 10
ARGF.readbyte  #=> end of file reached (EOFError)
 
               static VALUE
argf_readbyte(VALUE argf)
{
    VALUE c;

    NEXT_ARGF_FORWARD(0, 0);
    c = argf_getbyte(argf);
    if (NIL_P(c)) {
        rb_eof_error();
    }
    return c;
}
            
readchar → String or nil click to toggle source

Reads the next character from ARGF and returns it as a String. Raises an EOFError after the last character of the last file has been read.

For example:

$ echo "foo" > file
$ ruby argf.rb file

ARGF.readchar  #=> "f"
ARGF.readchar  #=> "o"
ARGF.readchar  #=> "o"
ARGF.readchar  #=> "\n"
ARGF.readchar  #=> end of file reached (EOFError)
 
               static VALUE
argf_readchar(VALUE argf)
{
    VALUE ch;

  retry:
    if (!next_argv()) rb_eof_error();
    if (TYPE(ARGF.current_file) != T_FILE) {
        ch = rb_funcall3(ARGF.current_file, rb_intern("getc"), 0, 0);
    }
    else {
        ch = rb_io_getc(ARGF.current_file);
    }
    if (NIL_P(ch) && ARGF.next_p != -1) {
        argf_close(ARGF.current_file);
        ARGF.next_p = 1;
        goto retry;
    }

    return ch;
}
            
readline(sep=$/) → string click to toggle source
readline(limit) → string
readline(sep, limit) → string

Returns the next line from the current file in ARGF.

By default lines are assumed to be separated by +$/+; to use a different character as a separator, supply it as a String for the sep argument.

The optional limit argument specifies how many characters of each line to return. By default all characters are returned.

An EOFError is raised at the end of the file.

 
               static VALUE
argf_readline(int argc, VALUE *argv, VALUE argf)
{
    VALUE line;

    if (!next_argv()) rb_eof_error();
    ARGF_FORWARD(argc, argv);
    line = argf_gets(argc, argv, argf);
    if (NIL_P(line)) {
        rb_eof_error();
    }

    return line;
}
            
readlines(sep=$/) → array click to toggle source
readlines(limit) → array
readlines(sep, limit) → array

Reads ARGF‘s current file in its entirety, returning an Array of its lines, one line per element. Lines are assumed to be separated by sep.

lines = ARGF.readlines
lines[0]                #=> "This is line one\n"
 
               static VALUE
argf_readlines(int argc, VALUE *argv, VALUE argf)
{
    VALUE line, ary;

    ary = rb_ary_new();
    while (!NIL_P(line = argf_getline(argc, argv, argf))) {
        rb_ary_push(ary, line);
    }

    return ary;
}
            
readpartial(maxlen) → string click to toggle source
readpartial(maxlen, outbuf) → outbuf

Reads at most maxlen bytes from the ARGF stream. It blocks only if ARGF has no data immediately available. If the optional outbuf argument is present, it must reference a String, which will receive the data. It raises EOFError on end of file.

readpartial is designed for streams such as pipes, sockets, and ttys. It blocks only when no data is immediately available. This means that it blocks only when following all conditions hold:

  • The byte buffer in the IO object is empty.

  • The content of the stream is empty.

  • The stream has not reached EOF.

When readpartial blocks, it waits for data or EOF. If some data is read, readpartial returns with the data. If EOF is reached, readpartial raises an EOFError.

When readpartial doesn’t block, it returns or raises immediately. If the byte buffer is not empty, it returns the data in the buffer. Otherwise, if the stream has some content, it returns the data in the stream. If the stream reaches EOF an EOFError is raised.

 
               static VALUE
argf_readpartial(int argc, VALUE *argv, VALUE argf)
{
    VALUE tmp, str, length;

    rb_scan_args(argc, argv, "11", &length, &str);
    if (!NIL_P(str)) {
        StringValue(str);
        argv[1] = str;
    }

    if (!next_argv()) {
        rb_str_resize(str, 0);
        rb_eof_error();
    }
    if (ARGF_GENERIC_INPUT_P()) {
        struct argf_call_arg arg;
        arg.argc = argc;
        arg.argv = argv;
        arg.argf = argf;
        tmp = rb_rescue2(argf_forward_call, (VALUE)&arg,
                         RUBY_METHOD_FUNC(0), Qnil, rb_eEOFError, (VALUE)0);
    }
    else {
        tmp = io_getpartial(argc, argv, ARGF.current_file, 0);
    }
    if (NIL_P(tmp)) {
        if (ARGF.next_p == -1) {
            rb_eof_error();
        }
        argf_close(ARGF.current_file);
        ARGF.next_p = 1;
        if (RARRAY_LEN(ARGF.argv) == 0)
            rb_eof_error();
        if (NIL_P(str))
            str = rb_str_new(NULL, 0);
        return str;
    }
    return tmp;
}
            
rewind → 0 click to toggle source

Positions the current file to the beginning of input, resetting ARGF.lineno to zero.

ARGF.readline   #=> "This is line one\n"
ARGF.rewind     #=> 0
ARGF.lineno     #=> 0
ARGF.readline   #=> "This is line one\n"
 
               static VALUE
argf_rewind(VALUE argf)
{
    if (!next_argv()) {
        rb_raise(rb_eArgError, "no stream to rewind");
    }
    ARGF_FORWARD(0, 0);
    return rb_io_rewind(ARGF.current_file);
}
            
seek(amount, whence=IO::SEEK_SET) → 0 click to toggle source

Seeks to offset amount (an Integer) in the ARGF stream according to the value of whence. See +IO#seek+ for further details.

 
               static VALUE
argf_seek_m(int argc, VALUE *argv, VALUE argf)
{
    if (!next_argv()) {
        rb_raise(rb_eArgError, "no stream to seek");
    }
    ARGF_FORWARD(argc, argv);
    return rb_io_seek_m(argc, argv, ARGF.current_file);
}
            
set_encoding(ext_enc) → ARGF click to toggle source
set_encoding("ext_enc:int_enc") → ARGF
set_encoding(ext_enc, int_enc) → ARGF
set_encoding("ext_enc:int_enc", opt) → ARGF
set_encoding(ext_enc, int_enc, opt) → ARGF

If single argument is specified, strings read from ARGF are tagged with the encoding specified.

If two encoding names separated by a colon are given, e.g. “ascii:utf-8”, the read string is converted from the first encoding (external encoding) to the second encoding (internal encoding), then tagged with the second encoding.

If two arguments are specified, they must be encoding objects or encoding names. Again, the first specifies the external encoding; the second specifies the internal encoding.

If the external encoding and the internal encoding are specified, the optional Hash argument can be used to adjust the conversion process. The structure of this hash is explained in the +String#encode+ documentation.

For example:

ARGF.set_encoding('ascii')         # Tag the input as US-ASCII text
ARGF.set_encoding(Encoding::UTF_8) # Tag the input as UTF-8 text
ARGF.set_encoding('utf-8','ascii') # Transcode the input from US-ASCII
                                   # to UTF-8.
 
               static VALUE
argf_set_encoding(int argc, VALUE *argv, VALUE argf)
{
    rb_io_t *fptr;

    if (!next_argv()) {
        rb_raise(rb_eArgError, "no stream to set encoding");
    }
    rb_io_set_encoding(argc, argv, ARGF.current_file);
    GetOpenFile(ARGF.current_file, fptr);
    ARGF.encs = fptr->encs;
    return argf;
}
            
skip → ARGF click to toggle source
Sets the current file to the next file in ARGV. If there aren't any more
files it has no effect.

For example:

$ ruby argf.rb foo bar
ARGF.filename  #=> "foo"
ARGF.skip
ARGF.filename  #=> "bar"
 
               static VALUE
argf_skip(VALUE argf)
{
    if (ARGF.init_p && ARGF.next_p == 0) {
        argf_close(ARGF.current_file);
        ARGF.next_p = 1;
    }
    return argf;
}
            
tell → Integer click to toggle source

Returns the current offset (in bytes) of the current file in ARGF.

ARGF.pos    #=> 0
ARGF.gets   #=> "This is line one\n"
ARGF.pos    #=> 17
 
               static VALUE
argf_tell(VALUE argf)
{
    if (!next_argv()) {
        rb_raise(rb_eArgError, "no stream to tell");
    }
    ARGF_FORWARD(0, 0);
    return rb_io_tell(ARGF.current_file);
}
            
to_a(sep=$/) → array click to toggle source
to_a(limit) → array
to_a(sep, limit) → array

Reads ARGF‘s current file in its entirety, returning an Array of its lines, one line per element. Lines are assumed to be separated by sep.

lines = ARGF.readlines
lines[0]                #=> "This is line one\n"
 
               static VALUE
argf_readlines(int argc, VALUE *argv, VALUE argf)
{
    VALUE line, ary;

    ary = rb_ary_new();
    while (!NIL_P(line = argf_getline(argc, argv, argf))) {
        rb_ary_push(ary, line);
    }

    return ary;
}
            
to_i → fixnum click to toggle source

Returns an integer representing the numeric file descriptor for the current file. Raises an ArgumentError if there isn’t a current file.

ARGF.fileno    #=> 3
 
               static VALUE
argf_fileno(VALUE argf)
{
    if (!next_argv()) {
        rb_raise(rb_eArgError, "no stream");
    }
    ARGF_FORWARD(0, 0);
    return rb_io_fileno(ARGF.current_file);
}
            
to_io → IO click to toggle source

Returns an IO object representing the current file. This will be a File object unless the current file is a stream such as STDIN.

For example:

ARGF.to_io    #=> #<File:glark.txt>
ARGF.to_io    #=> #<IO:<STDIN>>
 
               static VALUE
argf_to_io(VALUE argf)
{
    next_argv();
    ARGF_FORWARD(0, 0);
    return ARGF.current_file;
}
            
to_s → String click to toggle source

Returns “ARGF”.

 
               static VALUE
argf_to_s(VALUE argf)
{
    return rb_str_new2("ARGF");
}
            

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