L.SYS(5) L.SYS(5) NAME L.sys - UUCP remote host description file DESCRIPTION The _L_._s_y_s file is consulted by the UUCP daemon _u_u_c_i_c_o(8C) for informa‐ tion on remote systems. _L_._s_y_s includes the system name, appropriate times to call, phone numbers, and a login and password for the remote system. _L_._s_y_s is thus a privileged file, owned by the UUCP Administra‐ tor; it is accessible only to the Administrator and to the superuser. Each line in _L_._s_y_s describes one connection to one remote host, and has the form: System Times Caller Class Device/Phone_Number [Expect Send].... Fields can be separated by any number of blanks or tabs. Lines begin‐ ning with a ‘#’ character are comments; long lines can be continued by appending a ‘\’ character to the end of the line. The first five fields (_S_y_s_t_e_m through _D_e_v_i_c_e_/_P_h_o_n_e__N_u_m_b_e_r) specify the hardware mechanism that is necessary to make a connection to a remote host, such as a modem or network. _U_u_c_i_c_o searches from the top down through _L_._s_y_s to find the desired _S_y_s_t_e_m; it then opens the _L_- _d_e_v_i_c_e_s(5) file and searches for the first available device with the same _C_a_l_l_e_r, _C_l_a_s_s, and (possibly) _D_e_v_i_c_e. (‘‘Available’’ means that the device is ready and not being used for something else.) _U_u_c_i_c_o attempts a connection using that device; if the connection cannot be made (for example, a dialer gets a busy signal), _u_u_c_i_c_o tries the next available device. If this also fails, it returns to _L_._s_y_s to look for another line for the same _S_y_s_t_e_m. If none is found, _u_u_c_i_c_o gives up. _S_y_s_t_e_m is the hostname of the remote system. Every machine with which this system communicates via UUCP should be listed, regardless of who calls whom. Systems not listed in _L_._s_y_s will not be permitted a con‐ nection. The local hostname should not appear here for security rea‐ sons. _T_i_m_e_s is a comma-separated list of the times of the day and week that calls are permitted to this _S_y_s_t_e_m. _T_i_m_e_s is most commonly used to restrict long distance telephone calls to those times when rates are lower. List items are constructed as: _k_e_y_w_o_r_dhhmm-hhmm/_g_r_a_d_e;_r_e_t_r_y__t_i_m_e _K_e_y_w_o_r_d is required, and must be one of: Any Any time, any day of the week. Wk Any weekday. In addition, Mo, Tu, We, Th, Fr, Sa, and Su can be used for Monday through Sunday, respectively. Evening When evening telephone rates are in effect, from 1700 to 0800 Monday through Friday, and all day Saturday and Sunday. Evening is the same as Wk1700-0800,Sa,Su. Night When nighttime telephone rates are in effect, from 2300 to 0800 Monday through Friday, all day Saturday, and from 2300 to 1700 Sunday. Night is the same as Any2300-0800,Sa,Su0800-1700. NonPeak This is a slight modification of Evening. It matches when the USA X.25 carriers have their lower rate period. This is 1800 to 0700 Monday through Friday, and all day Saturday and Sunday. NonPeak is the same as Any1800-0700,Sa,Su. Never Never call; calling into this _S_y_s_t_e_m is forbidden or impossi‐ ble. This is intended for polled connections, where the remote system calls into the local machine periodically. This is nec‐ essary when one of the machines is lacking either dial-in or dial-out modems. The optional _h_h_m_m_-_h_h_m_m subfield provides a time range that modifies the keyword. _h_h_m_m refers to _h_o_u_r_s and _m_i_n_u_t_e_s in 24-hour time (from 0000 to 2359). The time range is permitted to "wrap" around midnight, and will behave in the obvious way. It is invalid to follow the Evening, NonPeak, and Night keywords with a time range. The _g_r_a_d_e subfield is optional; if present, it is composed of a ‘/’ (slash) and single character denoting the _g_r_a_d_e of the connection, from 0 to 9, A to Z, or a to z. This specifies that only requests of grade _g_r_a_d_e or better will be transferred during this time. (The grade of a request or job is specified when it is queued by _u_u_c_p or _u_u_x.) By con‐ vention, mail is sent at grade C, news is sent at grade d, and uucp copies are sent at grade n. Unfortunately, some sites do not follow these conventions, so it is not 100% reliable. The _r_e_t_r_y__t_i_m_e subfield is optional; it must be preceded by a ‘;’ (semicolon) and specifies the time, in minutes, before a failed connec‐ tion may be tried again. (This restriction is in addition to any con‐ straints imposed by the rest of the _T_i_m_e field.) By default, the retry time starts at 10 minutes and gradually increases at each failure, until after 26 tries _u_u_c_i_c_o gives up completely (MAX RETRIES). If the retry time is too small, _u_u_c_i_c_o may run into MAX RETRIES too soon. _C_a_l_l_e_r is the type of device used: ACU Automatic call unit or auto-dialing modem such as the Hayes Smartmodem 1200 or Novation ‘‘Smart Cat’’. See _L_-_d_e_v_i_c_e_s for a list of supported modems. DIR Direct connect; hardwired line (usually RS-232) to a remote system. MICOM Micom Terminal Switch. PAD X.25 PAD connection. PCP GTE Telenet PC Pursuit. See _L_-_d_e_v_i_c_e_s for configuration details. SYTEK Sytek high-speed dedicated modem port connection. TCP Berkeley TCP/IP or 3Com UNET connection. These are mutually exclusive. TCP ports do not need entries in _L_-_d_e_v_i_c_e_s since all the necessary information is contained in _L_._s_y_s. If sev‐ eral alternate ports or network connections should be tried, use multiple _L_._s_y_s entries. _C_l_a_s_s is usually the speed (baud) of the device, typically 300, 1200, or 2400 for ACU devices and 9600 for direct lines. Valid values are device dependent, and are specified in the _L_-_d_e_v_i_c_e_s file. On some devices, the baud may be preceded by a non-numeric prefix. This is used in _L_-_d_e_v_i_c_e_s to distinguish among devices that have iden‐ tical _C_a_l_l_e_r and baud, but yet are distinctly different. For example, 1200 could refer to all Bell 212-compatible modems, V1200 to Racal- Vadic modems, and C1200 to CCITT modems, all at 1200 baud. On TCP connections, _C_l_a_s_s is the port number (an integer number) or a port name from _/_e_t_c_/_s_e_r_v_i_c_e_s that is used to make the connection. For standard Berkeley TCP/IP, UUCP normally uses port number 540. _D_e_v_i_c_e_/_P_h_o_n_e__N_u_m_b_e_r varies based on the _C_a_l_l_e_r field. For ACU devices, this is the phone number to dial. The number may include: digits 0 through 9; # and * for dialing those symbols on tone telephone lines; - (hyphen) to pause for a moment, typically two to four seconds; = (equal sign) to wait for a second dial tone (implemented as a pause on many modems). Other characters are modem dependent; generally standard tele‐ phone punctuation characters (such as the slash and parentheses) are ignored, although _u_u_c_i_c_o does not guarantee this. The phone number can be preceded by an alphabetic string; the string is indexed and converted through the _L_-_d_i_a_l_c_o_d_e_s(5) file. For DIR devices, the _D_e_v_i_c_e_/_P_h_o_n_e__N_u_m_b_e_r field contains the name of the device in _/_d_e_v that is used to make the connection. There must be a corresponding line in _L_-_d_e_v_i_c_e_s with identical _C_a_l_l_e_r, _C_l_a_s_s, and _D_e_v_i_c_e fields. For TCP and other network devices, _D_e_v_i_c_e_/_P_h_o_n_e__N_u_m_b_e_r holds the true network name of the remote system, which may be different from its UUCP name (although one would hope not). _E_x_p_e_c_t and _S_e_n_d refer to an arbitrarily long set of strings that alter‐ nately specify what to _e_x_p_e_c_t and what to _s_e_n_d to login to the remote system once a physical connection has been established. A complete set of expect/send strings is referred to as an _e_x_p_e_c_t_/_s_e_n_d _s_c_r_i_p_t. The same syntax is used in the _L_-_d_e_v_i_c_e_s file to interact with the dialer prior to making a connection; there it is referred to as a _c_h_a_t _s_c_r_i_p_t. The complete format for one _e_x_p_e_c_t_/_s_e_n_d pair is: _e_x_p_e_c_t-_t_i_m_e_o_u_t-_s_e_n_d-_e_x_p_e_c_t-_t_i_m_e_o_u_t _s_e_n_d _E_x_p_e_c_t and _S_e_n_d are character strings. _E_x_p_e_c_t is compared against incoming text from the remote host; _s_e_n_d is sent back when _e_x_p_e_c_t is matched. By default, the _s_e_n_d is followed by a ‘\r’ (carriage return). If the _e_x_p_e_c_t string is not matched within _t_i_m_e_o_u_t seconds (default 45), then it is assumed that the match failed. The ‘_e_x_p_e_c_t-_s_e_n_d- _e_x_p_e_c_t’ notation provides a limited loop mechanism; if the first _e_x_p_e_c_t string fails to match, then the _s_e_n_d string between the hyphens is transmitted, and _u_u_c_i_c_o waits for the second _e_x_p_e_c_t string. This can be repeated indefinitely. When the last _e_x_p_e_c_t string fails, _u_u_c_i_c_o hangs up and logs that the connection failed. The timeout can (optionally) be specified by appending the parameter ‘~_n_n’ to the expect string, when _n_n is the timeout time in seconds. Backslash escapes that may be imbedded in the _e_x_p_e_c_t or _s_e_n_d strings include: \bGenerate a 3/10 second BREAK. \b_nWhere _n is a single-digit number; generate an _n/10 second BREAK. \cSuppress the \r at the end of a _s_e_n_d string. \dDelay; pause for 1 second. (_S_e_n_d only.) \rCarriage Return. \sSpace. \nNewline. \xxxWhere _x_x_x is an octal constant; denotes the corresponding ASCII character. As a special case, an empty pair of double-quotes "" in the _e_x_p_e_c_t string is interpreted as ‘‘expect nothing’’; that is, transmit the _s_e_n_d string regardless of what is received. Empty double-quotes in the _s_e_n_d string cause a lone ‘\r’ (carriage return) to be sent. One of the following keywords may be substituted for the _s_e_n_d string: BREAKGenerate a 3/10 second BREAK BREAK_nGenerate an _n/10 second BREAK CRSend a Carriage Return (same as ""). EOTSend an End-Of-Transmission character, ASCII \004. Note that this will cause most hosts to hang up. NLSend a Newline. PAUSEPause for 3 seconds. PAUSE_nPause for _n seconds. P_ODDUse odd parity on future send strings. P_ONEUse parity one on future send strings. P_EVENUse even parity on future send strings. (Default) P_ZEROUse parity zero on future send strings. Finally, if the _e_x_p_e_c_t string consists of the keyword ABORT, then the string following is used to arm an abort trap. If that string is subse‐ quently received any time prior to the completion of the entire _e_x_p_e_c_t_/_s_e_n_d script, then _u_u_c_i_c_o will abort, just as if the script had timed out. This is useful for trapping error messages from port selec‐ tors or front-end processors such as ‘‘Host Unavailable’’ or ‘‘System is Down.’’ For example: "" "" ogin:--ogin: nuucp ssword: ufeedme This is executed as, ‘‘When the remote system answers, _e_x_p_e_c_t nothing. _S_e_n_d a carriage return. _E_x_p_e_c_t the remote to transmit the string ‘ogin:’. If it doesn’t within 45 seconds, send another carriage return. When it finally does, _s_e_n_d it the string ‘nuucp’. Then _e_x_p_e_c_t the string ‘ssword:’; when that is received, _s_e_n_d ‘ufeedme’.’’ FILES /usr/lib/uucp/L.sys /usr/lib/uucp/UUAIDS/L.sysL.sys example SEE ALSO uucp(1C), uux(1C), L-devices(5), services(5), uucico(8C) BUGS ‘‘ABORT’’ in the send/expect script is expressed ‘‘backwards,’’ that is, it should be written ‘‘ _e_x_p_e_c_t ABORT’’ but instead it is ‘‘ ABORT _e_x_p_e_c_t’’. Several of the backslash escapes in the send/expect strings are confus‐ ing and/or different from those used by AT&T and Honey-Danber UUCP. For example, ‘\b’ requests a BREAK, while practically everywhere else ‘\b’ means backspace. ‘\t’ for tab and ‘\f’ for formfeed are not implemented. ‘\s’ is a kludge; it would be more sensible to be able to delimit strings with quotation marks. 4.3 Berkeley Distribution April 24, 1986 L.SYS(5)