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author | Cem Keylan <cem@ckyln.com> | 2021-03-09 08:43:43 +0300 |
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committer | Cem Keylan <cem@ckyln.com> | 2021-03-09 08:43:43 +0300 |
commit | 7ccc9c2432a847b85da5f445977d09f014cbc75b (patch) | |
tree | 8067d45ebeea60f1ddaa8167cb1398e2b6631473 /miscutils | |
parent | fef526c380e35cbdc0bdb8375487756c42659a75 (diff) | |
parent | 307cd26e9893ed0cf6ee88e7fca2d61d3da0e139 (diff) | |
download | busybox-master.tar.gz |
Diffstat (limited to 'miscutils')
-rw-r--r-- | miscutils/bc.c | 64 |
1 files changed, 58 insertions, 6 deletions
diff --git a/miscutils/bc.c b/miscutils/bc.c index 02a61ac49..553d0f472 100644 --- a/miscutils/bc.c +++ b/miscutils/bc.c @@ -138,11 +138,54 @@ //usage: //usage:#define dc_full_usage "\n" //usage: "\nTiny RPN calculator. Operations:" -//usage: "\n+, -, *, /, %, ~, ^," IF_FEATURE_DC_BIG(" |,") +//usage: "\nArithmetic: + - * / % ^" +//usage: IF_FEATURE_DC_BIG( +//usage: "\n~ - divide with remainder" +//usage: "\n| - modular exponentiation" +//usage: "\nv - square root" +//////// "\nA-F - digits 10..15 +//////// "\n_NNN - push negative number -NNN +//////// "\n[string] - push string (in FreeBSD, \[, \] and \\ are escapes, not implemented here and in GNU) +//////// "\nR - DC_LEX_POP pop and discard +//////// "\nc - DC_LEX_CLEAR_STACK clear stack +//////// "\nd - DC_LEX_DUPLICATE duplicate top-of-stack +//////// "\nr - DC_LEX_SWAP swap top-of-stack +//////// "\n:r - DC_LEX_COLON pop index, pop value, store to array 'r' +//////// "\n;r - DC_LEX_SCOLON pop index, fetch from array 'r', push +//////// "\nLr - DC_LEX_LOAD_POP pop register 'r', push +//////// "\nSr - DC_LEX_STORE_PUSH pop, push to register 'r' +//////// "\nlr - DC_LEX_LOAD read register 'r', push +//////// "\nsr - DC_LEX_OP_ASSIGN pop, assign to register 'r' +//////// "\n? - DC_LEX_READ read line and execute +//////// "\nx - DC_LEX_EXECUTE pop string and execute +//////// "\n<r - XC_LEX_OP_REL_GT pop, pop, execute register 'r' if top-of-stack was less +//////// "\n>r - XC_LEX_OP_REL_LT pop, pop, execute register 'r' if top-of-stack was greater +//////// "\n=r - XC_LEX_OP_REL_EQ pop, pop, execute register 'r' if equal +//////// "\n !<r !>r !=r - negated forms +//////// "\n >tef - "if greater execute register 't' else execute 'f'" +//////// "\nQ - DC_LEX_NQUIT pop, "break N" from macro invocations +//////// "\nq - DC_LEX_QUIT "break 2" (if less than 2 levels of macros, exit dc) +//////// "\nX - DC_LEX_SCALE_FACTOR pop, push number of fractional digits +//////// "\nZ - DC_LEX_LENGTH pop, push number of digits it has (or number of characters in string) +//////// "\na - DC_LEX_ASCIIFY pop, push low-order byte as char or 1st char of string +//////// "\n( - DC_LEX_LPAREN (FreeBSD, not in GNU) pop, pop, if top-of-stack was less push 1 else push 0 +//////// "\n{ - DC_LEX_LBRACE (FreeBSD, not in GNU) pop, pop, if top-of-stack was less-or-equal push 1 else push 0 +//////// "\nG - DC_LEX_EQ_NO_REG (FreeBSD, not in GNU) pop, pop, if equal push 1 else push 0 +//////// "\nN - DC_LEX_OP_BOOL_NOT (FreeBSD, not in GNU) pop, if 0 push 1 else push 0 +//////// FreeBSD also has J and M commands, used internally by bc +//////// "\nn - DC_LEX_PRINT_POP pop, print without newline +//////// "\nP - DC_LEX_PRINT_STREAM pop, print string or hex bytes +//usage: ) //usage: "\np - print top of the stack without popping" //usage: "\nf - print entire stack" -//usage: "\nk - pop the value and set the precision" +//////// "\nz - DC_LEX_STACK_LEVEL push stack depth +//////// "\nK - DC_LEX_SCALE push precision +//////// "\nI - DC_LEX_IBASE push input radix +//////// "\nO - DC_LEX_OBASE push output radix +//usage: IF_FEATURE_DC_BIG( +//usage: "\nk - pop the value and set precision" //usage: "\ni - pop the value and set input radix" +//usage: ) //usage: "\no - pop the value and set output radix" //usage: "\nExamples: dc -e'2 2 + p' -> 4, dc -e'8 8 * 2 2 + / p' -> 16" //usage: @@ -6217,13 +6260,20 @@ static unsigned long xc_program_len(BcNum *n) { size_t len = n->len; - if (n->rdx != len) return len; + if (n->rdx != len) + // length(100): rdx 0 len 3, return 3 + // length(0.01-0.01): rdx 2 len 0, return 2 + // dc: 0.01 0.01 - Zp: rdx 2 len 0, return 1 + return len != 0 ? len : (IS_BC ? n->rdx : 1); + + // length(0): return 1 + // length(0.000nnn): count nnn for (;;) { if (len == 0) break; len--; if (n->num[len] != 0) break; } - return len; + return len + 1; } static BC_STATUS zxc_program_builtin(char inst) @@ -6251,12 +6301,12 @@ static BC_STATUS zxc_program_builtin(char inst) if (inst == XC_INST_SQRT) s = zbc_num_sqrt(num, &res.d.n, G.prog.scale); #if ENABLE_BC - else if (len != 0 && opnd->t == XC_RESULT_ARRAY) { + else if (len && opnd->t == XC_RESULT_ARRAY) { bc_num_ulong2num(&res.d.n, (unsigned long) ((BcVec *) num)->len); } #endif #if ENABLE_DC - else if (len != 0 && !BC_PROG_NUM(opnd, num)) { + else if (len && !BC_PROG_NUM(opnd, num)) { char **str; size_t idx = opnd->t == XC_RESULT_STR ? opnd->d.id.idx : num->rdx; @@ -6265,6 +6315,8 @@ static BC_STATUS zxc_program_builtin(char inst) } #endif else { +//TODO: length(.00) and scale(.00) should return 2, they return 1 and 0 now +//(don't forget to check that dc Z and X commands do not break) bc_num_ulong2num(&res.d.n, len ? xc_program_len(num) : xc_program_scale(num)); } |