Cisco Catalyst 2960 Series, Configuration Manual

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EEM Policies and Cisco Error Number
Some EEM Tcl command extensions set a Cisco Error Number Tcl global variable _cerrno. Whenever _cerrno
is set, four other Tcl global variables are derived from _cerrno and are set along with it (_cerr_sub_num,
_cerr_sub_err, _cerr_posix_err, and _cerr_str).
For example, the action_syslog command in the example below sets these global variables as a side effect of
the command execution:
action_syslog priority warning msg
“
A sample message generated by action_syslog
”
if {$_cerrno != 0} {
set result [format "component=%s; subsys err=%s; posix err=%s;\n%s" \
$_cerr_sub_num $_cerr_sub_err $_cerr_posix_err $_cerr_str]
error $result
}
_cerrno: 32-Bit Error Return Values
The _cerrno set by a command can be represented as a 32-bit integer of the following form:
XYSSSSSSSSSSSSSEEEEEEEEPPPPPPPPP
For example, the following error return value might be returned from an EEM Tcl command extension:
862439AE
This number is interpreted as the following 32-bit value:
10000110001001000011100110101110
This 32-bit integer is divided up into the five variables shown in the table below.
Table 169: _cerrno: 32-Bit Error Return Value Variables
Description Variable
The error class (indicates the severity of the error).
This variable corresponds to the first two bits in the
32-bit error return value; 10 in the case above, which
indicates CERR_CLASS_WARNING:
See the table below for the four possible error class
encodings specific to this variable.
XY
The subsystem number that generated the most recent
error (13 bits = 8192 values). This is the next 13 bits
of the 32-bit sequence, and its integer value is
contained in $_cerr_sub_num. SSSSSSSSSSSSSS
Description Variable
The subsystem specific error number (8 bits = 256
values). This segment is the next 8 bits of the 32-bit
sequence, and the string corresponding to this error
number is contained in $_cerr_sub_err. EEEEEEEE
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
1788
How to Write Embedded Event Manager Policies Using Tcl