NAME sizeof - number of bytes required for value SYNOPSIS sizeof(x) TYPES x any return integer DESCRIPTION This is analogous to the C operator sizeof for the value only. It attempts to assess the number of bytes in memory used to store a value and all of its components. Unlike memsize(x), this builtin does not include the size of the overhead. Unlike size(x), this builtin includes the trailing \0 byte on the end of strings. For numeric values, sizeof(x) ignores the denominator if 'x' is an integer. For complex values, sizeof(x) ignores the imaginary part if 'x' is real. Because the 0, 1 and -1 numeric values are shared static values, sizeof(x) reports such values as having 0 bytes of storage. The number returned by sizeof(x) may be less than the actual number used because, for example, more memory may have been allocated for a string than is used: only the characters up to and including the first '\0' are counted in calculating the contribution of the string to sizeof(x). The number returned by sizeof(x) may be greater (and indeed substantially greater) than the number of bytes actually used. For example, after: a = sqrt(2); mat A[3] = {a, a, a}; the numerical information for a, A[0], A[1], A[2] are stored in the same memory, so the memory used for A is the same as if its 3 elements were null values. The value returned by sizeof(A) is calculated as A were defined by: mat A[3] = {sqrt(2), sqrt(2), sqrt(2)}. Similar sharing of memory occurs with literal strings. For associative arrays, only the value part of the name/value pair is counted. The minimum value for sizeof(x) occurs for the null and error values. EXAMPLES The results for examples like these will depend to some extent on the system being used. The following were for an SGI R4k machine in 32-bit mode: ; print sizeof(null()), sizeof(0), sizeof(3), sizeof(2^32 - 1), sizeof(2^32) 8 68 68 68 72 ; x = sqrt(2, 1e-100); print sizeof(x), sizeof(num(x)), sizeof(den(x)) 148 108 108 ; print sizeof(list()), sizeof(list(1)), sizeof(list(1,2)) 28 104 180 ; print sizeof(list()),sizeof(list(1)),sizeof(list(1,2)),sizeof(list(1,2,3)) 28 104 180 256 ; mat A[] = {1}; mat B[] = {1,2}; mat C[] = {1,2,3}; mat D[100,100]; ; print sizeof(A), sizeof(B), sizeof(C), sizeof(D) 124 192 260 680056 ; obj point {x,y,z} ; obj point P = {1,2,3}; print sizeof(P) 274 LIMITS It is assumed sizeof(x) will fit into a system long integer. LINK LIBRARY none SEE ALSO size, fsize, strlen, digits ## Copyright (C) 1999 Landon Curt Noll ## ## Calc is open software; you can redistribute it and/or modify it under ## the terms of the version 2.1 of the GNU Lesser General Public License ## as published by the Free Software Foundation. ## ## Calc is distributed in the hope that it will be useful, but WITHOUT ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY ## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General ## Public License for more details. ## ## A copy of version 2.1 of the GNU Lesser General Public License is ## distributed with calc under the filename COPYING-LGPL. You should have ## received a copy with calc; if not, write to Free Software Foundation, Inc. ## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. ## ## Under source code control: 1996/05/24 02:04:04 ## File existed as early as: 1996 ## ## chongo /\oo/\ http://www.isthe.com/chongo/ ## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/