std.stdio.readln
- multiple declarations
Function readln
Read line from stdin
.
S readln(S)
(
dchar terminator = '\x0a'
)
if (isSomeString!S);
This version manages its own read buffer, which means one memory allocation per call. If you are not
retaining a reference to the read data, consider the readln(buf)
version, which may offer
better performance as it can reuse its read buffer.
Returns
The line that was read, including the line terminator character.
Parameters
Name | Description |
---|---|
S | Template parameter; the type of the allocated buffer, and the type returned. Defaults to string . |
terminator | Line terminator (by default, '\n' ). |
Note
String terminators are not supported due to ambiguity with readln(buf) below.
Throws
StdioException
on I/O error, or UnicodeException
on Unicode conversion error.
Example
Reads stdin
and writes it to stdout
.
import std .stdio;
void main()
{
string line;
while ((line = readln()) !is null)
write(line);
}
Function readln
Read line from stdin
and write it to buf[], including terminating character.
size_t readln(C)
(
ref C[] buf,
dchar terminator = '\x0a'
)
if (isSomeChar!C && is(Unqual!C == C) && !is(C == enum));
size_t readln(C, R)
(
ref C[] buf,
R terminator
)
if (isSomeChar!C && is(Unqual!C == C) && !is(C == enum) && isBidirectionalRange!R && is(typeof(terminator .front == (dchar) .init)));
This can be faster than line = readln()
because you can reuse
the buffer for each call. Note that reusing the buffer means that you
must copy the previous contents if you wish to retain them.
Returns
size_t
0 for end of file, otherwise number of characters read
Parameters
Name | Description |
---|---|
buf | Buffer used to store the resulting line data. buf is resized as necessary. |
terminator | Line terminator (by default, '\n' ). Use newline
for portability (unless the file was opened in text mode). |
Throws
StdioException
on I/O error, or UnicodeException
on Unicode conversion error.
Example
Reads stdin
and writes it to stdout
.
import std .stdio;
void main()
{
char[] buf;
while (readln(buf))
write(buf);
}
Authors
Walter Bright, Andrei Alexandrescu, Alex Rønne Petersen