Parameters
S | Template parameter; the type of the allocated buffer, and the type returned. Defaults to string. |
terminator | Line terminator (by default, '\n'). |
readln
fn
S readln(S = string)(dchar terminator = '\n') if (isSomeString!S)Read line from stdin.
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.
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);
}fn
size_t readln(C)(ref C[] buf, dchar terminator = '\n') if (isSomeChar!C && is(Unqual!C == C) && !is(C == enum))Read line from stdin and write it to buf[], including terminating character.
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
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);
}