mawk-code - dumping mawk's byte-code

mawk-code - dumping mawk's byte-code

As mawk executes the program, it maintains a reference to the command to execute in cdp. After that there may be data and/or references in cdp[0], cdp[1], etc. When an operation requires operands, mawk pushes the values (or array/string references) onto the stack, which updates the stack pointer sp. When the operation completes, mawk consumes those entries on the stack, pushing the result (if any) onto the stack. While executing user-defined functions, mawk maintains a framepointerfp to address the function's local variables. a_catConcatenatearray-indices. Usage: Forms a multiple array index by concatenating the elements of sp[1-cnt..0], with each element separated by SUBSEP. Parameters: cdp[0] cnt, the number of elements to concatenate follows the command. sp[0]..sp[1-cnt] hold reference to the elements to concatenate. Returns the index in sp[0]. a_delDeleteanarrayitem. Usage: delete array[expr] Parameters: sp[0] points to array sp[-1] is an expra_lengthFindthelengthofanarray. Usage: length(array) Parameters: sp[0] points to array. Returns the length of the array in sp[0]. a_pushaPusharrayaddressontostack. Usage: This is used to set up a calling argument for a function. Parameters: cdp[0] array reference follows the command. Returns the array in sp[0]. a_testTestifanexpressionispresentinanarray. Usage: (expression in array) Parameters: sp[0] points to anarray. sp[-1] is an expression. Returns 1 in sp[0] if the expression is found, 0 otherwise. addAddtwonumbers. Usage: first + second Parameters: sp[0] holds the second value. sp[-1] holds the first value. Returns the sum in sp[0]. add_asgCombinedaddition/assignment. Usage: target += source Parameters: sp[0] is the source expression sp[-1] points to the target Stores the sum in the target, leaving sp[0] pointing to the target. ae_pushaPushreferencetoarraycell,givenexpressionforitsindex. Usage: arrayname[expression] Parameters: cdp[0] an array reference follows the command. sp[0] has an expression, used for the index of a cell in the array. Returns a reference to the addressed cell in sp[0]. ae_pushiPushcontentsofarraycell,givenexpressionforitsindex. Usage: arrayname[expression] Parameters: sp[0] has an expression, used for the index of a cell in the array. Returns contents of the addressed cell in sp[0]. aloopUpdatereferencetonextcellforarrayloop. Usage: for ( i in arrayname ) statement Parameters: none Mawk maintains a stack of array-loop state. It updates the array/cell references in the current loop's state. assignAssignsavalue. Usage: target = source Parameters: sp[0] is the source expression sp[-1] points to the target Stores the sum in the target, leaving sp[0] pointing to the target. atan2Computearc-tangentoftwovalues. Usage: atan2( first, second ) Parameters: sp[0] holds the second value sp[-1] holds the first value Returns the result in sp[0]. callCallafunction. Usage: function() Parameters: cdp[0] is a reference to the function block cdp[1] holds number of input arguments Returns function value in sp[0]. catConcatenatetwostrings. Usage: firstsecond Parameters: sp[0] is the second string. sp[-1] is the first string. Returns the result in sp[0]. closeClosethefileorpipeassociatedwithanexpression. Usage: close( expression ) Parameters: sp[0] holds the expression identifying the file to close Returns the status from closing the file, 0 on success or -1 on failure. cosComputethecosineofavalueinradians. Usage: cos( value ) Parameters: sp[0] is the value. Returns the result in sp[0]. del_aDeleteanarray. Usage: delete(array) Parameters: sp[0] is the array to delete. divDivideonenumberbyanother. Usage: first / second Parameters: sp[0] is the second value. sp[-1] is the first value. Returns the quotient in sp[0]. div_asgCombineddivision/assignment. Usage: target /= source Parameters: sp[0] is the source sp[-1] points to the target Stores the quotient in the target, leaving sp[0] pointing to the target. eqComparetwovalues. Usage: first == second Parameters: sp[0] is the second value sp[-1] is the first value Returns 1 in sp[0] if the values are equal, otherwise 0. exitExitsmawkwithaspecificexit-code. Usage: exit(exit_code) Parameters: sp[0] is the exit_codeexit0Exitsmawkwithsuccess Usage: exit Parameters: none expComputebase-eexponentialfunctionofavalue. Usage: exp( value ) Parameters: sp[0] is the value Returns the result in sp[0]. f_add_asgCombinationaddition/assignmenttoNF. Usage: NF += expression Parameters: sp[0] is the expression to add f_assignAssignanexpressiontoNF. Usage: NF = expression Parameters: sp[0] is the expressionf_div_asgCombinationdivision/assignmenttoNF. Usage: NF /= expression Parameters: sp[0] is the expressionf_mod_asgCombinationmodulus/assignmenttoNF. Usage: NF %= expression Parameters: sp[0] is the expressionf_mul_asgCombinationmultiplication/assignmenttoNF. Usage: NF *= expression Parameters: sp[0] is the expressionf_post_decPost-decrementusingNF. Usage: NF-- Parameters: holds a reference to the field to use f_post_incPost-incrementusingNF. Usage: NF++ Parameters: holds a reference to the field to use f_pow_asgExponentiationusingNF. Usage: NF ^= expression Parameters: sp[0] is the expression to use f_pre_decPredecrementusingNF. Usage: --NF Parameters: sp[0] holds a reference to the field to use f_pre_incPreincrementusingNF. Usage: ++NF Parameters: sp[0] holds a reference to the field to use f_pushaPusharrayreferencetodatasplit-upasfields.. Usage: $0 = expression getline Parameters: cdp[0] is a reference to the data to be split/assigned. Returns the resulting array reference in sp[0]. f_pushiPushcontentsofnumberedfield. Usage: $expression Parameters: cdp[0] holds a reference to $expression cdp[1] holds expression Returns the field's value in sp[0]. f_sub_asgCombinationsubtraction/assignmenttoNF. Usage: NF -= expression Parameters: sp[0] holds a reference to the field to use fe_pushaPushreferencetonumberedfield. Usage: $number Parameters: sp[0] holds the field number Returns a reference to the field in sp[0]. fe_pushiPushcontentofnumberedfield. Usage: $number Parameters: sp[0] holds the field number Returns the field's content in sp[0]. fflushFlushtheoutputfileorpipeassociatedwithanexpression. Usage: fflush( expression ) Parameters: sp[0] is the expression value Returns the result in sp[0]. gtTestiffirstvalueisgreaterthanthesecond. Usage: first > second Parameters: sp[0] holds the second value. sp[-1] holds the first value. Returns 1 in sp[0] if the first value is greater than, otherwise 0. gteTestiffirstvalueisgreaterthanorequaltothesecond. Usage: first >= second Parameters: sp[0] holds the second value. sp[-1] holds the first value. Returns 1 in sp[0] if the first value is greater than or equal, otherwise 0. indexFindthepositionofthesecondstringinthefirst. Usage: index( first, second ) Parameters: sp[0] is the second string sp[0] is the first string Returns the position in sp[0] starting at 1 if found, 0 if not found. intReturnsavaluetruncatedtowardszero.. Usage: int( value ) Parameters: sp[0] is the value Returns the result in sp[0]. jmainGofromBEGINcodetoMAINcode. Usage: (internal state) Parameters: none jmpJumptoanewbyte-codeposition,byagivennumberofbytes. Usage: (internal state) Parameters: cdp[0] holds the (signed) number of bytes by which to jump. jnzJumptoanewbyte-codepositionifsp[0]isnonzero,byagivennumberofbytes. Usage: (internal state) Parameters: cdp[0] holds the (signed) number of bytes by which to jump. sp[0] holds a value to compare against 0. jzJumptoanewbyte-codepositionifsp[0]iszero,byagivennumberofbytes. Usage: (internal state) Parameters: cdp[0] holds the (signed) number of bytes by which to jump. sp[0] holds a value to compare against 0. l_pushaPushalocaladdressontotheevaluationstack. Usage: (internal state) Parameters: cdp[0] holds the offset from the framepointerfp. Returns the address in sp[0]. l_pushiPushcontentsofalocalvariableontotheevaluationstack. Usage: (internal state) Parameters: cdp[0] holds the offset from the framepointerfp. Returns the contents of the local variable in sp[0]. la_pushaPushesareferencetoanarrayontotheevaluationstack. Usage: arrayname Parameters: cdp[0] holds the offset from the framepointerfp of a reference to an array. Returns a reference to the array in sp[0]. lae_pushaPushesareferencetoagivenarraycellontotheevaluationstack. Usage: arrayname[expression] Parameters: cdp[0] holds the offset from the framepointerfp of a reference to an array. sp[0] holds an expression Returns a reference to the specified array cell in sp[0]. lae_pushiPushesthecontentsofagivenarraycellontotheevaluationstack. Usage: arrayname[expression] Parameters: cdp[0] holds the offset from the framepointerfp of a reference to an array. sp[0] holds an expression Returns the contents of the specified array cell in sp[0]. lengthReturnsthelengthofastringorarrayvalue. Usage: length( value ) Parameters: sp[0] is the string or array reference Returns the length in sp[0]. ljnzSpecialjumpforlogical-OR,alwaysprecededbytest. Usage: (internal state) Parameters: cdp[0] holds the (signed) number of bytes by which to jump if the value is nonzero. sp[0] holds a value to compare against 0. ljzSpecialjumpforlogical-OR,alwaysprecededbytest. Usage: (internal state) Parameters: cdp[0] holds the (signed) number of bytes by which to jump if the value is zero. sp[0] holds a value to compare against 0. logComputethenaturallogarithmofavalue. Usage: log( value ) Parameters: sp[0] is the value Returns the result in sp[0]. ltTestiffirstvalueislessthanthesecond. Usage: first < second Parameters: sp[0] holds the second value. sp[-1] holds the first value. Returns 1 in sp[0] if the first value is less than, otherwise 0. lteTestiffirstvalueislessthanorequaltothesecond. Usage: first <= second Parameters: sp[0] holds the second value. sp[-1] holds the first value. Returns 1 in sp[0] if the first value is less than or equal, otherwise 0. match0Testif$0matchesagivenregularexpression. Usage: $0 ~ regex Parameters: cdp[0] holds a reference to a regular expression. Returns 1 in sp[0] if $0 matches the regular expression, 0 otherwise. match1Testifagivenexpressionmatchesagivenregularexpression. Usage: expression ~ regex Parameters: cdp[0] holds a reference to a regular expression. sp[0] holds an expression to test. Returns 1 in sp[0] if the expression matches the regular expression, 0 otherwise. match2Testifanexpressioninsp[-1]matchestheregularexpressioninsp[0]. Usage: expression ~ regex Parameters: sp[0] holds a reference to a regular expression. sp[-1] holds an expression to test. Returns 1 in sp[0] if the expression matches the regular expression, 0 otherwise. mktimeConvertsadatespecificationinsystimeformattoatimestamp. Usage: mktime( string ) Parameters: sp[0] holds the date-specification string Returns the result in sp[0]. modComputemodulus/remainderwithtwooperands. Usage: first % second Parameters: sp[0] holds the second operand sp[-1] holds the first operand Returns the remainder in sp[0]. mod_asgAssignmodulus/remainderwithtwooperands. Usage: first %= second Parameters: sp[0] holds the second operand cdp[0] holds the first operand Returns the remainder in sp[0] as well as replacing the first value. mulComputeproductwithtwooperands. Usage: first * second Parameters: sp[0] holds the second value sp[-1] holds the first value Returns the product in sp[0]. mul_asgAssignproductwithtwooperands. Usage: first *= second Parameters: sp[0] holds the second value sp[-1] holds the first value Returns the product in sp[0] as well as replacing the first value. neqComparetwovalues. Usage: first != second Parameters: sp[0] is the second value sp[-1] is the first value Returns 1 in sp[0] if the values are not equal, otherwise 0. nextReadthenextrecord,restartpatterntesting. Usage: next Parameters: none nextfileBeginprocessingthenextfilelistedonthecommandline. Usage: nextfile Parameters: none nf_pushiPushthenumberoffields(NF)ontotheevaluationstack. Usage: (internal state) Parameters: none notComputealogicalnegation. Usage: ! value Parameters: sp[0] holds a value to negate. Returns the result on the evaluation stack, i.e., 0 if the value is nonzero and 1 otherwise. ol_glReadinto$0usinggetline. Usage: getline Parameters: none ol_gl_nrReadinto$0usinggetline,updatingNRandFNR. Usage: getline < file Parameters: none omainStartexecutingthemainsectionofthescript(betweenBEGINandEND). Usage: (internal state) Parameters: none popPoptheevaluationstack,discardingthevalue. Usage: (internal state) Parameters: none pop_alFinishanarray“in”loop,deallocatingthestateinformation. Usage: (internal state) Parameters: none post_decPost-decrementavalue. Usage: value -- Parameters: sp[0] holds the value to decrement Returns the updated value in sp[0]. post_incPost-incrementavalue. Usage: value ++ Parameters: sp[0] holds the value to increment Returns the updated value in sp[0]. powComputethefirstvalueraisedtothepowerofthesecondvalue. Usage: first ^ second Parameters: sp[0] holds the second value sp[-1] holds the first value Returns the result in sp[0]. pow_asgAssignthefirstvalueraisedtothepowerofthesecondvalue. Usage: variable = first ^ second Parameters: cdp[0] is a reference to the variable which will be assigned the result sp[0] holds the second value sp[-1] holds the first value pre_decPre-decrementavalue. Usage: -- value Parameters: sp[0] holds the value to decrement. Returns the updated value in sp[0];. pre_incPre-incrementavalue. Usage: ++ value Parameters: sp[0] holds the value to decrement. Returns the updated value in sp[0];. pushaPusharrayaddressontostack. Usage: (internal state) Parameters: cdp[0] array reference follows the command. Returns the array in sp[0]. pushcPushadatacellontotheevaluationstack. Usage: (internal state) Parameters: cdp[0] is a reference to the data to push Returns a reference to the result in sp[0]. pushdPushadoublefloatingvalueontotheevaluationstack. Usage: (internal state) Parameters: cdp[0] is a reference to the data to push Returns a reference to the result in sp[0]. pushiPushcontentsofnextreferencedvariableontotheevaluationstack. Usage: (internal state) Parameters: cdp[0] is a reference to the data cell to copy. Returns a reference to the result in sp[0]. pushintReservethenextslotontheevaluationstack,settingitstype. Usage: (internal state) Parameters: cdp[0] holds the type to set in the new slot, e.g., for data via I/O redirection Returns a reference to the result in sp[0]. pushsPushareferencetoastringvalueontotheevaluationstack. Usage: (internal state) Parameters: cdp[0] holds a reference to the string value Returns a reference to the result in sp[0]. randReturnsarandomnumberbetweenzeroandone.. Usage: rand() Parameters: none Returns the result in sp[0]. rangeTestarangepattern:pat1,pat2{action}. Usage: (internal state) Parameters: cdp[0].op a flag, test pat1 if on else pat2 cdp[1].op offset of pat2 code from cdp cdp[2].op offset of action code from cdp cdp[3].op offset of code after the action from cdp cdp[4] start of pat1 code sp[0] holds arguments for the action. retReturnafunctionvalue. Usage: return value Parameters: sp[0] holds the return value When calling a function, mawk saves the current stack, creating a new one. On return, mawk restores the previous stack and returns the function value in sp[0]. ret0Returnfromafunctionwithoutprovidingareturn-value. Usage: return Parameters: sp[0] is modified to make the value uninitialized. As in the ret operation, mawk restores the previous stack. After the return, sp[0] is an uninitialized value. set_alBeginanarray“in”loop. Usage: for ( iterator in arrayname ) statement Parameters: sp[0] holds a reference to the array sp[-1] holds a reference to the iteration variable Mawk pushes a new entry onto the array loop stack, and updates cdp to point to the statement to execute. sinComputethesineofavalueinradians. Usage: sin( value ) Parameters: sp[0] holds the value Returns the result in sp[0]. sprintfReturnsastringconstructedfromexpression-listaccordingtoformat. Usage: sprintf( format [, value1 [,... ] ] ) Parameters: sp[0] is the last parameter value; there can be up to 255. Returns the resulting string in sp[0]. sqrtReturnsthesquarerootofavalue. Usage: sqrt( value 0 Parameters: sp[0] is the value Returns the result in sp[0]. srandSeedstherandomnumbergenerator. Usage: srand( value ) srand( ) Parameters: sp[0] is the seed value, which may be uninitialized Returns the previous seed value in sp[0]. stopFinisharangepattern. Usage: (internal state) Parameters: none strftimeFormatsthegiventimestampusingthegivenformat. Usage: strftime( format , timestamp , utc ) strftime( format , timestamp ) strftime( format ) strftime( ) Parameters: Zero to three parameters may be on the stack. If all three are used, they are as follows: sp[0] is the utc flag sp[-1] is the timestamp value sp[-2] is the format Returns the result in sp[0]. subSubtractthesecondvaluefromthefirst. Usage: first - second Parameters: sp[0] holds the second value sp[-1] holds the first value Returns the result in sp[0]. sub_asgAssignthedifferenceoftwovaluestoavariable. Usage: target = first - second Parameters: cdp[0] holds a reference to the variable to which to assign the result sp[0] holds the second value sp[-1] holds the first value Stores the difference in the target, leaving sp[0] pointing to the target. substreturnsthesubstringofstrings,startingatindexi,oflengthn. Usage: substr(s,i,n) substr(s,i) Parameters: Two or three parameters may be on the stack. If all three are used, they are as follows: sp[0] holds the length n. sp[0] holds the index i. sp[0] holds the string s. systemExecutesacommand,returningthewait-status. Usage: status = system( command ) Parameters: sp[0] is the command to execute Returns the wait-status in sp[0]. systimeReturnsthecurrenttimeofdayasthenumberofsecondssincetheEpoch. Usage: systime( ) Parameters: none Returns the result in sp[0]. testTestalogicalexpression. Usage: value Parameters: sp[0] holds a value to test. Returns the result on the evaluation stack, i.e., 1 if the value is nonzero and 0 otherwise. tolowerCopyastring,convertingtolowercase. Usage: tolower( value ) Parameters: sp[0] is the value to convert Returns the result in sp[0]. toupperCopyastring,convertingtouppercase. Usage: toupper( value ) Parameters: sp[0] is the value to convert Returns the result in sp[0]. uminusUnitaryminus. Usage: - value Parameters: sp[0] contains a value to negate. As a side-effect, if the value is a string, it is cast to double floating point. Returns the result in sp[0]. uplusUnitaryplus. Usage: + value Parameters: sp[0] contains a value to use. As a side-effect, if the value is a string, it is cast to double floating point. Returns the result in sp[0].

M_1J mandatory jump M_2JA optional (undesirable) jump M_2JB optional (desirable) jump M_2JC pop position, optional jump (to continue looping) if advanced M_ACCEPT end of match M_ANY arbitrary character (.) M_CLASS character class M_END end of string ($) M_ENTER prepare an iteration by resetting the counter. This precedes a M_SAVE_POS. M_LOOP Like M_2JC, this is the last part of a conditional loop. It is used where one or both of the minimum and maximum iterations are known. M_SAVE_POS push position onto stack, at the beginning of a loop M_START start of string (^) M_STR matching a literal string M_U arbitrary string (.*) Version 1.3.4 2025-01-30 MAWK-CODE(7)

At startup, mawk compiles the script into byte-code. After that, it interprets the compiled byte-code. Use the -Wdump option to show the byte-code.