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table(2) System Calls Manual table(2) NAME table - Examines or updates elements from a system table. SYNOPSIS #include <sys/table.h> int table(id, index, addr, nel, lel) long id; long index; void *addr; long nel; u_long lel; PARAMETERS The ID of the system table that contains the element or elements. The index of an element within the table. The address of a struct (or a struct array) of the appropriate type to copy the element values to (on examine) or from (on update). The various structure layouts are de- scribed in /usr/include/sys/table.h. A signed number that specifies how many elements to copy and in which direction. A positive value copies the elements from the kernel to addr. A negative value copies the elements from addr to the kernel. The expected size of a single element. DESCRIPTION The table() interface is used to examine or update one or more elements in the system table. The system table is specified by id and the starting element is specified by index. The table() interface copies the element value or values to or from the specified addr. The nel parameter specifies the number of elements to copy, starting from index. A positive value indicates an examine oper- ation. The elements are copied from the kernel to addr. A negative value indicates an update operation. The elements are copied from addr to the kernel. The lel parameter specifies the expected element size. If multiple el- ements are specified, successive addresses are calculated for addr by incrementing it by lel for each element copied. If the size of a given element is larger than lel, table() truncates excess data on an update (from addr to the kernel) and stores only the expected size on an exam- ine (from the kernel to addr). If the size of a given element is smaller than lel, table() copies only the valid data on an update and pads the element value on an examine. The table() interface guarantees that an update operation will not change the offset and size of any field within an element. New fields are added only at the end of an element. The table() interface returns a count of the elements examined or up- dated. The id TBL_PROCINFO allows you to determine the actual number of elements in a table before requesting any data; call table() with lel set to zero (0) and nel to the maximum positive integer. The id parameter must specify one of the following tables, each of which has a structure in <sys/table.h> unless otherwise noted. The controlling terminal device number table. The index is by process ID and exactly one element can be requested. If the process ID is zero (0), the current process is indexed. Only 0 and the current process ID are supported. The element is of type dev_t as defined in <sys/types.h>. This table is examine only. It cannot be updated. The U-area table. The index is by process ID. See the user.h header file for the (pseudo) struct user that is returned. The system load average vector (pseudo) table. The index must be zero (0) and exactly one ele- ment can be requested. If the scale is zero (0), the load average vector is the float- ing point variant. If the size is non-zero, the load average vector has been scaled by the indicated factor (typically 1000) to produce the long integer variant. This table is examine only. It cannot be updated. The system include file version number (pseudo) table. The index must be zero (0) and exactly one element can be requested. The include version is a unique integer. It identifies the layout of kernel data structures that are imported by certain kernel-dependent programs. This table is examine only. It cannot be updated. The process com- mand argument table containing the saved arguments for processes. The index is by process ID and exactly one element can be requested. Arguments for processes other than the cur- rent process can be accessed only by the superuser. This table is examine only. It cannot be updated. All the command line arguments for the process. Specify the process id in the index argument. The addr argument points to a buffer into which the command line arguments are placed. The amount of buffer space needed for the command line arguments depends on the total length of all the arguments from the process being examined. Specify the size of the user buffer with the lel argument. If the buffer is not large enough to ac- cept the complete argument list, the given length of the buffer is copied. The arguments are placed in the buffer as a series of null-ter- minated strings, in argument order. The maximum process count per user ID table. The index is by process ID and exactly one element can be requested. If the process ID is zero (0), the current process is indexed. Only 0 and the current process ID are supported. The element is of the short integer type. The maximum count includes all processes running under the cur- rent user ID even though the limit affects only the current process and any children created with that limit in effect. The limit can be changed only by the superuser. The process status information table. The index is an offset into a table of processes. Status information for processes other than the cur- rent process can be accessed only by the superuser. This table is examine only. It cannot be updated. Each element in the ta- ble is a tbl_procinfo structure. This id lets you determine the actual number of elements in a table before you request any data. You call table with the lel argument set to zero and the nel argument set to the maximum positive integer. The return is the number of elements in the table. The process environment table. The index is by process ID and exactly one element can be requested. Environment infor- mation for processes other than the current process can be ac- cessed only by the superuser. This table is examine only. It cannot be updated. The system time information table. The in- dex must be zero (0) and exactly one element can be requested. The system information table contains ticks of time accumulated in the various system states: user, nice, system, and idle. The system tick frequency and profiling (if configured) frequency are also provided for conversion from ticks to time values. This table is examine only. It cannot be updated. The disk statistics table. The index is by disk number. This table is examine only. It cannot be updated. The table is the structure tbl_dkinfo. The system swap device list information table. This table is examine only. It cannot be updated. If the index is positive or zero (0), the swap device information for the entry in the swap device list is returned. If the index is less than zero (0), the amount of total swap space configured and amount of total free space on the system is returned. In addition, the flags field contains the value of vm_swap_eager flag and the dev field contains the lazy swap de- vice number (if lazy swap) or zero (0) (if eager swap). The TTY statistics table. The index must be zero (0) and exactly one element can be requested. This table is examine only. It can- not be updated. The message queue ID table. The index is the index into the queue array. Each element is a msqid_ds struc- ture as defined in msqid_ds(). This table is examine only. Its elements cannot be updated. The semaphore ID table. The index is the index into the array of semaphore IDs. Each element is a semid_ds structure as defined in semid_ds(). This table is ex- amine only. Its elements cannot be updated. The shared memory region ID table. The index is the index into the array of shared memory region IDs. Each element is a shmid_ds structure as defined in shmid_ds(). This table is examine only. Its ele- ments cannot be updated. The message information table. This table is examine only. Its elements cannot be updated. The message information structure is defined in <sys/msg.h>. The index is by field positions within the message information structure, as follows: The maximum message size The maximum num- ber of bytes on the queue The number of message queue identi- fiers The number of system message headers The semaphore infor- mation table. This table is examine only. It cannot be up- dated. The semaphore information structure is defined in <sys/sem.h>. The index is by field position within the semaphore information structure as follows: The number of semaphore identifiers The maximum number of semaphores per identifier The maximum number of operations per semop() call The maximum number of undo en- tries per process The semaphore maximum value The maximum adjust on exit value The shared memory information table. This table is examine only. It cannot be updated. The shared memory in- formation structure is defined in <sys/shm.h>. The index is by field position within the shared memory informa- tion structure, as follows: The maximum shared memory region size The minimum shared memory region size The number of shared memory identifiers The maximum number of attached shared memory regions per process The system interrupt information table. There is no index into the table. This table is examine only. It cannot be updated. RETURN VALUES A positive return value indicates that the call succeeded for that num- ber of elements. A return value of -1 indicates that an error oc- curred, and an error code is stored in the global location errno. ERRORS The addr parameter specifies an invalid address. The table specified by id is not defined. The index value is not valid for the specified table. The specified table allows only an index of the current process ID with exactly one element. Some other index or element number was specified. An element length of zero (0) was supplied for the TBL_AR- GUMENTS table. An attempt was made to update an examine-only table. An attempt was made to change the maximum number of processes or the account ID, and the caller was not the superuser. The process speci- fied by a process ID index cannot be found. RELATED INFORMATION acct(2) delim off table(2)