* io.c (rb_io_popen): update the document for the first argument and

exceptions.

* process.c (rb_f_exec, rb_f_system): update the document for
  exceptions.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@6540 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

io.c

@@ -2798,23 +2798,27 @@ rb_io_popen(str, argc, argv, klass)
 
 /*
  *  call-seq:
- *     IO.popen(cmd_string, mode="r" )               => io
- *     IO.popen(cmd_string, mode="r" ) {|io| block } => obj
+ *     IO.popen(cmd, mode="r")               => io
+ *     IO.popen(cmd, mode="r") {|io| block } => obj
  *
- *  Runs the specified command string as a subprocess; the subprocess's
+ *  Runs the specified command as a subprocess; the subprocess's
  *  standard input and output will be connected to the returned
- *  <code>IO</code> object. If <i>cmd_string</i> starts with a
+ *  <code>IO</code> object.  If _cmd_ is a +String+
  *  ``<code>-</code>'', then a new instance of Ruby is started as the
- *  subprocess. The default mode for the new file object is ``r'', but
- *  <i>mode</i> may be set to any of the modes listed in the description
- *  for class IO.
+ *  subprocess.  If <i>cmd</i> is an +Array+ of +String+, then it will
+ *  be used as the subprocess's +argv+ bypassing a shell.  The default
+ *  mode for the new file object is ``r'', but <i>mode</i> may be set
+ *  to any of the modes listed in the description for class IO.
+ *
+ *  Raises exceptions which <code>IO::pipe</code> and
+ *  <code>Kernel::system</code> raise.
  *
  *  If a block is given, Ruby will run the command as a child connected
  *  to Ruby with a pipe. Ruby's end of the pipe will be passed as a
  *  parameter to the block. In this case <code>IO::popen</code> returns
  *  the value of the block.
  *
- *  If a block is given with a <i>cmd_string</i> of ``<code>-</code>'',
+ *  If a block is given with a _cmd_ of ``<code>-</code>'',
  *  the block will be run in two separate processes: once in the parent,
  *  and once in a child. The parent process will be passed the pipe
  *  object as a parameter to the block, the child version of the block
@@ -2825,8 +2829,11 @@ rb_io_popen(str, argc, argv, klass)
  *     f = IO.popen("uname")
  *     p f.readlines
  *     puts "Parent is #{Process.pid}"
- *     IO.popen ("date") { |f| puts f.gets }
+ *     IO.popen("date") { |f| puts f.gets }
  *     IO.popen("-") {|f| $stderr.puts "#{Process.pid} is here, f is #{f}"}
+ *     IO.popen(%w"sed -e s|^|<foo>| -e s&$&;zot;&", "r+") {|f|
+ *       f.puts "bar"; f.close_write; puts f.gets
+ *     }
  *
  *  <em>produces:</em>
  *
@@ -2835,6 +2842,7 @@ rb_io_popen(str, argc, argv, klass)
  *     Wed Apr  9 08:53:52 CDT 2003
  *     26169 is here, f is
  *     26166 is here, f is #<IO:0x401b3d44>
+ *     <foo>bar;zot;
  */
 
 static VALUE

process.c

@@ -1225,6 +1225,9 @@ rb_check_argv(argc, argv)
  *  used, so the running command may inherit some of the environment of
  *  the original program (including open file descriptors).
  *
+ *  Raises SystemCallError if the _command_ couldn't execute (typically
+ *  <code>Errno::ENOENT</code> when it was not found).
+ *
  *     exec "echo *"       # echoes list of files in current directory
  *     # never get here
  *
@@ -1573,11 +1576,10 @@ rb_spawn(argc, argv)
  *  call-seq:
  *     system(cmd [, arg, ...])    => true or false
  *
- *  Executes _cmd_ in a subshell, returning +true+ if
- *  the command was found and ran successfully, +false+
- *  otherwise. An error status is available in <code>$?</code>. The
- *  arguments are processed in the same way as for
- *  <code>Kernel::exec</code>.
+ *  Executes _cmd_ in a subshell, returning +true+ if the command ran
+ *  successfully, +false+ otherwise. An error status is available in
+ *  <code>$?</code>. The arguments are processed in the same way as
+ *  for <code>Kernel::exec</code>, and raises same exceptions as it.
  *
  *     system("echo *")
  *     system("echo", "*")