telnetdReadLine(3TELD)

NAME | SYNOPSIS | API RESTRICTIONS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | SEE ALSO

NAME

telnetdReadLine- Read a line of characters from a TELNET session

SYNOPSIS

$(OS_DIR)/lib/libtelnetd.a
#include <arpa/telnetd.h>

int telnetdReadLine(telnetdSessionHandle *hdl, void *buf, unsigned int nchar, int echo, char *prompt);

API RESTRICTIONS

The function or functions documented here may not be used safely in all application contexts with all APIs provided in the ChorusOS 5.0 product.

See API(5FEA) for details.

DESCRIPTION

The telnetdReadLine() function attempts to read a line of characters from the TELNET session designated by the hdl handle, into the buffer pointed to by buf. A line is delimited by a NEWLINE (ASCII LF) character. This means that telnetdReadLine() will not complete until an entire line has been typed. However, nchar indicates the maximum number of characters to be read. Any number of characters may be requested in telnetdReadLine() (even one character), without losing information. Also, no matter how many characters are requested by the call, a maximum of one line will be returned.

If the value of echo is not zero, characters read from the TELNET session will be echoed on the user terminal. If the value of echo is zero, no echoing will be performed.

If prompt is not the NULL pointer, telnetdReadLine() first writes the string (terminated by a null character) pointed to by prompt on the TELNET connection.

If the TELNET session has no data available and the connection socket has O_NONBLOCK set, telnetdReadLine() returns -1 and sets errno to EAGAIN. Otherwise telnetdReadLine() blocks until a line of characters becomes available.

As described in telnetdRead(), the application should check if on return of telnetdReadLine() the state of the virtual terminal has changed, and get the new state by calling telnetdGetTermState().

RETURN VALUE

On successful completion, telnetdReadLine() returns the number of characters actually read and placed in the buffer; this number may be less than nchar. Otherwise it returns -1 and sets errno to indicate the error.

ERRORS

errno is set to EINVAL if telnetdReadLine is called with an invalid hdl handle.

The telnetdReadLine function may fail and set errno to any of the errors specified for the telnetdRead(3TELD) and telnetdWrite(3TELD) functions.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	Evolving

SEE ALSO

telnetdGetTermState(3TELD), telnetdRead(3TELD), telnetdWrite(3TELD)

ChorusOS 5.0  Last Revised December 2001

NAME | SYNOPSIS | API RESTRICTIONS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | SEE ALSO