aq_pp: Record preprocessor

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Synopsis

aq_pp [-h] Global_Opt Input_Spec Prep_Spec Process_Spec Output_Spec

Global_Opt:
     [-verb] [-stat] [-test]

Input_Spec:
     [-f[,AtrLst] File [File ...]] [-d ColSpec [ColSpec ...]] |
     [-exp[,AtrLst]|-cnt[,AtrLst] DbName[:TabName] [ExpOpts ...] --]
     [-cat[,AtrLst] File [File ...] ColSpec [ColSpec ...]]

Prep_Spec:
    [-seed RandSeed]
    [-var ColSpec Val]
    [-alias ColName AltName]
    [-renam ColName NewName]

Process_Spec:
    [-eval ColSpec|ColName Expr]
    [-mapf[,AtrLst] ColName MapFrom] [-mapc ColSpec|ColName MapTo]
    [-kenc ColSpec|ColName ColName [ColName ...]]
    [-kdec ColName ColSpec|ColName[+] [ColSpec|ColName[+] ...]]
    [-filt FilterSpec]
    [-map[,AtrLst] ColName MapFrom MapTo]
    [-sub[,AtrLst] ColName File [File ...] [ColSPec ...]]
    [-grep[,AtrLst] ColName File [File ...] [ColSPec ...]]
    [-cmb[,AtrLst] File [File ...] ColSpec [ColSpec ...]]
    [-pmod ModSpec [ModSrc]]

Output_Spec:
    [-o[,AtrLst] File] [-c ColName [ColName ...]]
    [-ovar[,AtrLst] File [-c ColName [ColName ...]]]
    [-imp[,AtrLst] DbName[:TabName] [-server AdrSpec [AdrSpec ...]] [-local]
    [-mod ModSpec [ModSrc]]

Description

aq_pp is a stream-based record processing tool. It loads and processes records on at a time through these simple steps:

  • First, it reads data from the input in various formats (e.g., CSV) according to the input spec.
  • Then it converts the input into an internal data row according to the column spec.
  • The row is then passed through a processing chain according to the processing spec.
  • The data row, or any of its columns, can be output at any point in the chain. A row can also be output multiple times with varying values, or it needs not be output at all.

Other characteristics of the tool include:

  • Columns are typed – numbers, string and IP. Column operations are also type specific.
  • Besides the input columns, new columns can be added dynamically through the processing chain.
  • Variables can also be added dynamically. They differ from columns in that their values persist across input rows, while column values are updated at each row. For example, a variable can be used to calculate the sum of a column over all rows in a data set.
  • A variety of processing options are supported to populate and modify column values. An example is -eval which sets a column’s value according to the evaluated result of an expression.
  • A variety of processing options are supported to select (or filter) data rows. An example is -filt which filters-in records according to the logical result of an expression.
  • Custom modules can be used to augment processing. One module type supplies custom processing functions for use in evaluation expressions. Another module type operates on the data row directly.
  • Conditional processing groups can be used to control execution within the chain. For example, a -filt can control whether to perform a -eval. Even the outputs can be controlled this way.
  • Result can go to files, stdout and/or another processing layer called Udb.

With its stream-based design, aq_pp can process an unlimited amount of data using a constant amount of memory. For this reason, it is well suited for the pre-processing of large amount of raw data, where the extracted and transformed result is used to generate higher level analytics.

Options

-test

Test command line arguments and exit. If specified twice (-test -test), a more throughout test will be attempted. For example, the program will try to load lookup files and connect to Udb in test mode.

    • If all specs are good, the exit code will be 0.
    • If there is an error, the exit code will be non-zero. Usually, an error message will also be printed to stderr.

-verb

Verbose – print program progress to stderr while processing. Usually, a marker is printed for each 10,000,000 records processed.

-stat

Print a record count summary line to stderr at the end of processing. The line has the form:

aq_pp: rec=Count err=Count out=Count

-f[,AtrLst] File [File …]

Set the input attributes and files. See the aq_tool input specifications manual for details.

Example:

$ aq_pp ... -f,+1l file1 file2 ...

Skip the first line from both files before loading.

-d ColSpec [ColSpec …]

Define the input data columns. See the aq_tool input specifications manual for details. In general, ColSpec has the form Type[,AtrLst]:ColName.

Supported Types are:

    • S – String.
    • F – Double precision floating point.
    • L – 64-bit unsigned integer.
    • LS – 64-bit signed integer.
    • I – 32-bit unsigned integer.
    • IS – 32-bit signed integer.
    • IP – v4/v6 address.

Optional AtrLst is a comma separated list of column specific attributes. ColName is the column name (case insensitive). It can contain up to 31 alphanumeric and ‘_’ characters. Its first character cannot be a digit.

Example:

$ aq_pp ... -d s:Col1 s,lo:Col2 i,trm:Col3 ...
    • Col1 is a string. Col2 is also a string, but the input value will be converted to lower case. Col3 is an unsigned integer, the trm attribute removes blanks around the value before it is converted to an internal number.

-exp[,AtrLst]|-cnt[,AtrLst] DbName[:TabName] [ExpOpts …] —

Get the input data from an Udb export or count operation. This will set the data source as well as the column definitions, so -f`_ and -d are not needed. DbName is the database name (see Target Udb Database). TabName is a table/vector name in the database to export. If TabName is not given or if it is a ”.” (a dot), the primary keys will be exported/counted. Optional AtrLst is a comma separated list containing:

    • spec=UdbSpec – Set the spec file directly (see Target Udb Database).

ExpOpts are the -exp or -cnt related options as decribed in aq_udb (except -o which is not applicable here). A — must be specified following the last ExpOpts. Options given after — will be interpreted as aq_pp options.

Example:

$ aq_pp ... -exp mydb:Test -filt 'Col3 > 123456789' -- ...
$ aq_pp ... -exp mydb:Test -- -filt 'Col3 > 123456789' ...
    • Use Test’s data as the input. The two examples produce the same result. However, the first form is more efficient because the filter is done inside Udb so that less data is processed by aq_pp.

-cat[,AtrLst] File [File …] ColSpec [ColSpec …]

Add rows from Files to the -f data set. The file and column specifications are the same as in the -f and -d options. See the aq_tool input specifications manual for details.

Note that the columns need not be the same as those from -d (by name). If they differ, a super set is constructed. Multiple -cat can be used such that the final data set will contain unique columns from -d and all -cat. Columns that do not exist in a data set will be set to zero or blank when that data set is loaded.

Example:

$ aq_pp ... -d s:Col1 s:Col2 i:Col3 s:Col4 ...
-cat more.csv i:Col3 s:Col1 s:Col5 s:Col6
...
    • Add data from “more.csv”. Column Col3 and Col1 are common, so the resulting data set will have Col1, Col2, Col3, Col4, Col5 and Col6. Since the main data set does not have Col5 and Col6, they are set to blank when it is loaded. Similarly, since “more.csv” does not have Col2 and Col4, they are set to blank when it is loaded.

-seed RandSeed

Set the random sequence seed of the $Random evaluation builtin variable. Default seed is 1.

-var ColSpec Val

Define a new variable and initialize its value to Val. A variable stores a value that persists between rows over the entire run. Recall that normal column values change from row to row. ColSpec is the variable’s spec in the form Type:ColName where Type is the data type and ColName is the variable’s name, see -d for details. Note that a string Val must be quoted, see String Constant spec for details.

A variable can also be used in conjunction with -o,fvar VarName to specify a dynamic output target (the variable must be a string in this case). See the fvar description under -o for details.

Example:

$ aq_pp ... -d i:Col1 ...
-var 'i:Sum' 0 ...
-eval 'Sum' 'Sum + Col1' ...
    • Initialize variable Sum to 0, then update the rolling sum for each row.

–alias ColName AltName

Set a column alias. “ ColName“ refers to a previously defined column/variable/alias. AltName is the desired alias. An alias allow the same column to be addressed using multiple names. If the original column is no longer needed, use -renam instead.

-renam ColName NewName

Rename a column or an alias. “ ColName“ refers to a previously defined column/variable/alias. NewName is the new name of the column/variable/alias. addressed using multiple names.

-eval ColSpec|ColName Expr

Evaluate Expr and save the result to a column. The column can be a new column, an existing column/variable or null as explained below.

    • If a – is given, the result will not be saved anywhere. This is useful when calling a function that puts its result in destinated columns by itself.
    • If ColSpec is given, a new column will be created using the spec. See -d for details. Note that the new column cannot participate in Expr.
    • If “ ColName“ is given, it must refer to a previously defined column/variable.

Expr is the expression to evaluate. Data type of the evaluated result must be compatible with the data type of the target column. For example, string result for a string column and numeric result for a numeric column (there is no automatic type conversion; however, explicit conversion can be done using the To*() functions described below). Operands in the expression can be the names of previously defined columns or variables, constants, builtin variables and functions.

    • Column names are case insensitive. Do not quote the name.
    • String constants must be quoted, see String Constant spec for details.
    • Use ‘(‘ and ‘)’ to group operations as appropriate.
    • For a numeric type evaluation, supported operators are ‘*’, ‘/’, ‘%’, ‘+’, ‘-‘, ‘&’, ‘|’ and ‘^’.
    • Depending on the operand type, evaluation may use 64-bit floating point arithmetic or 64-bit signed integral arithmetic. For example, “1 + 1” is evaluated using integral arithmetic while “1 + 1.0” is evaluated using floating point arithmetic. Similarly, “Col1 + 1” may use either arithmetic depending on Col1’s type while “Col1 + 1.0” always uses floating point.
    • For a string type evaluation, the only supported operator is ‘+’ for concatenation.
    • Certain types can be converted to one another using the builtin functions ToIP(), ToF(), ToI() and ToS().
    • Operator precedence is NOT supported. Use ‘(‘ and ‘)’ to group operations as appropriate.

Builtin variables:

$Random

A random number (postive integer). Its value changes every time the variable is referenced. The seed of this random sequence can be set using the -seed option.

$RowNum

The input row index (one-based).

$CurSec

The current time in seconds. It is evaluated in realtime when the variable is referenced.

$CurUSec

The current time in microseconds. It is evaluated in realtime when the variable is referenced.

Standard functions:

See aq-emod for a list of supported functions.

Example:

$ aq_pp ... -d i:Col1 ... -eval l:Col_evl 'Col1 * 10' ...
    • Set new column Col_evl to 10 times the value of Col1.
$ aq_pp ... -d s:Col1 s:Col2 ...
-eval is:Dt 'DateToTime(Col2, "Y.m.d.H.M.S.p") - DateToTime(Col1, "Y.m.d.H.M.S.p")'
...
    • Col1 and Col2 are date strings of the form “Year/Month/day Hour:Min:Sec AM”. Dt will contain the time difference in seconds.

-mapf[,AtrLst] ColName MapFrom

Extract data from a string column. This option should be used in conjunction with -mapc. ColName is a previously defined column/variable to extract data from. MapFrom defines the extraction rule. Optional AtrLst is a comma separated list containing:

    • ncas – Do case insensitive match (default is case sensitive). For ASCII data only.
    • One or more regular expression attributes.

If any of the regular expression related attributes are enabled, then MapFrom must use the RegEx MapFrom Syntax. Otherwise, it must use the RT MapFrom Syntax.

-mapc ColSpec|ColName MapTo

Render data extracted via previous -mapf into a new column or into an existing column/variable. The column must be of string type.

    • If ColSpec is given, a new column will be created using the spec. See -d for details.
    • If ColName is given, it must refer to a previously defined column/variable.

MapTo is the rendering spec. See MapTo Syntax for details.

Example:

$ aq_pp ... -d s:Col1 s:Col2 s:Col3 ...
-mapf Col1 '%%v1_beg%%.%%v1_end%%'
-mapf,rx Col2 '\(.*\)-\(.*\)'
-mapf,rx Col3 '\(.*\)_\(.*\)'
-mapc s:Col_beg '%%v1_beg%%,%%1%%,%%4%%'
-mapc s:Col_end '%%v1_end%%,%%2%%,%%5%%'
...
    • Extract data from Col1, Col2 and Col3. Then put “parts” of these columns in two new columns. Note that the RegEx based MapFrom expressions do not have named placeholders for the extracted data. Placeholders are interpreted implicitly from the the expressions in this way.
    • %%0%% – Represent the entire match in the first -mapf,rx (not used in example).
    • %%1%% – Represent the 1st subpattern match in the first -mapf,rx.
    • %%2%% – Represent the 2nd subpattern match in the first -mapf,rx.
    • %%3%% – Represent the entire match in the second -mapf,rx (not used in example).
    • %%4%% – Represent the 1st subpattern match in the second -mapf,rx.
    • %%5%% – Represent the 2nd subpattern match in the second -mapf,rx.

-kenc ColSpec|ColName ColName [ColName …]

Encode a key column from the given ColNames. The key column must be of string type. The encoded value it stores constains binary data.

    • If ColSpec is given, a new column will be created using the spec. See -d for details.
    • If ColName is given, it must refer to a previously defined column/variable.

The source ColNames must be previously defined. They can have any data type.

Example:

$ aq_pp ... -d s:Col1 i:Col2 ip:Col3 ...
-kenc s:Key1 Col1 Col2 Col3
...
    • Compose a new “composite” column Key1 from Col1, Col2 and Col3.

-kdec ColName ColSpec|ColName[+] [ColSpec|ColName[+] …]

Decode a key column given by ColName into one or more columns given by ColSpec (new column) or ColName (existing column/variable). The key ColName must be an existing string column/variable. For the decode-to columns, possible specs are:

Type:ColName[+]

Extract column value into the newly defined column. With an optional ‘+’, the extracted value will also be encoded back into the key.

ColName[+]

Extract column value into an existing column or variable. With an optional ‘+’, the extracted value will also be encoded back into the key.

Type:[+]

Like specifying a new column, but with a blank column name. This means that the extracted value will not be saved in another column. With an optional ‘+’, the extracted value will be encoded back into the key.

Note that the decode-to column types must match those used in the original -kenc spec.

Example:

$ aq_pp ... -d s:Key1 ...
-kdec Key1 s:Col1 i:Col2 ip:Col3
...
    • Extract Col1, Col2 and Col3 from Key1.
$ aq_pp ... -d s:Key1 ...
-kdec Key1 s: i:Col2 ip:
...
    • Extract only Col2 from Key1. Since there is no ‘+’ in the extract-to spec, the value of Key1 is NOT altered.
$ aq_pp ... -d s:Key1 ...
-kdec Key1 s: i:Col2+ ip:+
-kdec Key1 i: ip:Col3
...
    • In the first rule, Col2 is extracted from Key1. At the same time, the 2nd and 3rd fields are encoded back into Key1. In the second rule. Col3 is extracted from the new value of Key1.

-filt FilterSpec

Filter (or select) records based on FilterSpec. FilterSpec is a logical expression that evaluates to either true or false for each record – if true, the record is selected; otherwise, it is discarded. It has the basic form [!] LHS [<compare> RHS] where:

    • The negation operator ! negates the result of the comparison. It is recommended that !(…) be used to clarify the intended operation even though it is not required.
    • LHS and RHS can be:
      • A column/variable name (case insensitive). Do not quote the name.
      • A constant, which can be a string, a number or an IP address. A string constant must be quoted, see String Constant spec for details.
      • An expression to evaluate as defined under -eval.
    • If only the LHS is given, its values will be used as a boolean – a non blank string or non zero number/IP equals True, False otherwise.
    • Supported comparison operators are:
      • ==, >, <, >=, <= – LHS and RHS comparison.
      • ~==, ~>, ~<, ~>=, ~<= – LHS and RHS case insensitive comparison; string type only.
      • !=, !~= – Negation of the above equal operators.
      • &= – Perform a “(LHS & RHS) == RHS” check; numeric types only.
      • !&= – Negation of the above.
      • & – Perform a “(LHS & RHS) != 0” check; numeric types only.
      • !& – Negation of the above.

More complex expression can be constructed by using (…) (grouping), ! (negation), || (or) and && (and). For example:

LHS_1 == RHS_1 && !(LHS_2 == RHS_2 || LHS_3 == RHS_3)

Example:

$ aq_pp ... -d s:Col1 s:Col2 i:Col3 s:Col4 ...
-filt 'Col1 === Col4 && Col2 != "" && Col3 >= 100'
...
    • Only keep records whose Col1 and Col4 are the same (case insensitive) and Col2 is not blank and Col3’s value is greater than or equal to 100.

-map[,AtrLst] ColName MapFrom MapTo

Remap (a.k.a., rewrite) a string column’s value. ColName is a previously defined column/variable. MapFrom defines the extraction rule. MapTo is the rendering spec. See MapTo Syntax for details. Optional AtrLst is a comma separated list containing:

    • ncas – Do case insensitive match (default is case sensitive). For ASCII data only.
    • One or more regular expression attributes.

If any of the regular expression related attributes are enabled, then MapFrom must use the RegEx MapFrom Syntax. Otherwise, it must use the RT MapFrom Syntax.

Example:

$ aq_pp ... -d s:Col1 ...
-map Col1 '%%v1_beg%%-%*' 'beg=%%v1_beg%%'
...
$ aq_pp ... -d s:Col1 ...
-map,rx Col1 '\(.*\)-*' 'beg=%%1%%'
...
    • Both commands rewrite Col1 in the same way.

-sub[,AtrLst] ColName File [File …] [ColSpec …]

Replace the values of ColName, a string column in the current data set, with values from a lookup table loaded from Files. Optional AtrLst is a comma separated list containing:

    • Standard input attributes described in the aq_tool input specifications manual.
    • ncas – Do case insensitive match (default is case sensitive). For ASCII data only.
    • pat – Support ‘?’ and ‘*’ wild cards in the “From” value. Literal ‘?’, ‘*’ and ‘\’ must be escaped by a ‘\’. Without this attribute, “From” value is assumed constant and no escape is necessary.
    • req – Discard records not matching any entry in the lookup table. Normally, column value will remain unchanged if there is no match.
    • all – Use all matches. Normally, only the first match is used. With this attribute, one row is produced for each match.

ColSpecs define the input columns as described in the aq_tool input specifications manual. The spec is optional, default is “S:from S:to” (or just “from to”). If a spec is defined, it must include these 2 columns (by name):

    • from – Marks the column used to match the value of ColName. It must have a string type.
    • to – Marks the column used as the new value of ColName. It must have a string type.

The from values are generally literals. Patterns can be used if the pat attribute description above is set. The to values are always literals. Matches are carried out according to the order of the match value in the files. Match stops when the first match is found. If the files contain both exact value and pattern, then:

    • Exact values are matched first, skipping over any interleaving patterns.
    • Patterns are matched next, skipping over any interleaving fixed values.

Example:

$ aq_pp ... -d s:Col1 ... -sub Col1 lookup.csv TO X FROM ...
    • Substitute Col1 according to lookup table. The data in the lookup table is not in the default “from to” format, so the column spec must be given. The X in the spec marks an unneeded column.

–grep[,AtrLst] ColName File [File …] [ColSpec …]

Filter by matching the value of ColName, a string column in the current data set, against the values loaded from Files. Optional AtrLst is a comma separated list containing:

    • Standard input attributes described in the aq_tool input specifications manual.
    • ncas – Do case insensitive match (default is case sensitive). For ASCII data only.
    • pat – Support ‘?’ and ‘*’ wild cards in the “From” value. Literal ‘?’, ‘*’ and ‘\’ must be escaped by a ‘\’. Without this attribute, match value is assumed constant and no escape is necessary.
    • rev – Reverse logic, select records that do not match.

ColSpecs define the input columns as described in the aq_tool input specifications manual. The spec is optional, default is “S:from” (or just “from”). If a spec is defined, it must include 1 column (by name):

    • from – Marks the column used to match the value of ColName. It must have a string type.

The from values are generally literals. Patterns can be used if the pat attribute description above is set. Matches are carried out according to the order of the match value in the files. Match stops when the first match is found. If the files contain both exact value and pattern, then:

    • Exact values are matched first, skipping over any interleaving patterns.
    • Patterns are matched next, skipping over any interleaving fixed values.

Example:

$ aq_pp ... -d s:Col1 ... -grep,rev Col1 lookup.csv X X FROM ...
    • Select (or retain) only records whose Col1 values are not in lookup table. The data in the lookup table is not in the default format, so the column spec must be given. The X‘s in the spec mark the unneeded columns.

-cmb[,AtrLst] File [File …] ColSpec [ColSpec …]

Combine data from Files into the current data set by joining rows from both data sets. The new data set will contain unique columns from both sets. Common columns are automatically used as the join keys (see ColSpec description on how to customize join keys). Optional AtrLst is a comma separated list containing:

    • Standard input attributes described in the aq_tool input specifications manual.
    • ncas – Do case insensitive match (default is case sensitive). For ASCII data only.
    • req – Discard unmatched records.
    • all – Use all matches. Normally, only the first match is used. With this attribute, one row is produced for each match.
    • mrg – Use merge mode. Records in the current data set and in in the combine files must already be sorted according to the combine keys in the same order (default is ascending unless dec is given). Use this approach if the combine data is too large to fit into memory.
    • dec – Same as mrg except that all the data are sorted in descending order.

ColSpecs define the input columns as described in the aq_tool input specifications manual. with these column attribute extensions:

    • key – Marks a column as being a join key. It must be a common column. This is the default for a common column.
    • cmb – Marks a column to be combined into the current data set. This is the default for a non-common column. It is typically used to mark a common column as not a join key.

Example:

$ aq_pp ... -d s:Col1 s:Col2 i:Col3 s:Col4 ...
-cmb lookup.csv i:Col3 s:Col1 s:Col5 s:Col6
...

Combine lookup.csv into the data set according to composite key <Col3, Col1>. The resulting data set will have columns Col1, Col2, Col3, Col4, Col5 and Col6.

$ aq_pp ... -d s:Col1 s:Col2 i:Col3 s:Col4 ...
-cmb lookup.csv i:Col3 s:Col1 s:Col5 s:Col6 s,cmb:Col2
...
$ aq_pp ... -d s:Col1 s:Col2 i:Col3 s:Col4 ...
-cmb lookup.csv i,key:Col3 s,key:Col1 s,cmb:Col5 s,cmb:Col6 s,cmb:Col2
...
    • Both are the same as the previous example, except that Col2 is explicitly set as a combine column. That is, its value will originally come from the current data set, then it will be overwritten if there is a match from the lookup table.

-pmod ModSpec [ModSrc]

Use the processing function in the given module to process the current record. The function is typically used to implement custom logics.

    • Retrieve and/or modify one or more columns in the current data row.
    • Filter out the current data row.
    • Generate multiple output rows from the current row.
    • Stop processing.

ModSpec has the form ModName or ModName(“Arg1”, “Arg2”, …) where ModName is the module name and Arg* are module dependent arguments. Note that the arguments must be string constants; for this reason, they must be quoted according to the string constant spec.

ModSrc is an optional module source file. It can be:

    • A module script source file that can be used to build the specified module. See the aq_pp module script compiler documentation for more information.
    • A ready-to-use module object file. It must have a .so extension.

Without ModSrc, aq_pp will look for a preinstalled module matching ModName. Standard modules:

unwrap_strv(“From_Col”, “From_Sep”, “To_Col” [, “AtrLst”])

Unwrap a delimiter separated string column into none or more values. The row will be replicated for each of the unwrapped values. This module requires 3 or 4 arguments:

      • From_Col – Column containing the string value to unwrap. It must have type S.
      • From_Sep – The single byte delimiter that separate individual values. The delimiter must be given as-is, no escape is recognized.
      • To_Col – Column to save each unwrapped value to. It must have type S. The To_Col can be the same as the From_Col – the module will remember the original From_Col value.
      • AtrLst – Optional. A comma separated attribute list containing:
        • relax – No trailing delimiter. One is expected by default.
        • noblank – Skip blank values. Blanks are kept by default.

[-o[,AtrLst] File] [-c ColName [ColName …]]

Output data rows. Multiple sets of “-o … -c …” can be specified.

Optional “-o[,AtrLst] File” sets the output attributes and file. See the aq_tool output specifications manual for details. In addition, the following attribute is supported:

    • fvar – Output to a dynamically defined target. File is the name of a previously defined string variable. The actual target file is obtained from the value of the variable. The initial value of the variable sets the initial file. Subsequently, when the value of the variable changes, the old output will be closed and the new one will be opened.

Optional “-c ColName [ColName …]” selects the columns to output. Normally, each selection is the name of a previously defined column/variable. In addition, these special forms are supported:

    • * – An asterisk adds all columns (except variables) to the output.
    • ColName[:NewName][+NumPrintFormat] – Add ColName to the output. If :NewName is given, it will be used as the output label. The +NumPrintFormat spec is for numeric columns. It overrides the print format of the column (be careful with this format – a wrong spec can crash the program).
    • ^ColName[:NewName][+NumPrintFormat] – Same as the above, but with a leading ^ mark. It is used to modify the output label and/or format of a previously selected output column called ColName. If ^ColName[…] is the first selection after -c, then * will be included automatically first.
    • ~ColName – The leading ~ mark is used to exclude a previously selected output column called ColName. If ~ColName is the first selection after -c, then * will be included automatically first.

If -o is given without a -c, then * is assumed. If -c is given without a prior -o, the selected columns will be output to stdout.

Example:

$ aq_pp ... -d s:Col1 s:Col2 s:Col3 ... -o - -c Col2 Col1
    • Output Col2 and Col1 (in that order) to stdout.
$ aq_pp ... -d s:Col1 s:Col2 s:Col3 ... -c ^Col1:ColX ~Col3
    • First, select * (Col1, Col2 and Col3) implicitly. Then change Col1’s label to ColX. Then exclude Col3. The final output columns are ColX and Col2.
$ aq_pp ... -d s:Col1 s:Col2 s:Col3 ... -var i:Col4 0 -c '*' Col4
    • First, select * (Col1, Col2 and Col3) explicitly. Then add the variable Col4.
$ aq_pp ... -var s:out1 '"first.csv"' ...
-if -filt '...' -eval out1 '...' -endif ... -o,fvar out1 ...
    • Define the output target as the value of variable out1.
    • Change the variable’s value conditionally via a -if … -endif group. The conditional group and/or the -eval statement can be replaced by other means of changing out1 as well.
    • Sometimes, the initial value of out1 is not known until run time. If so, set its value to /dev/null in the -var statement.

-ovar[,AtrLst] File [-c ColName [ColName …]]

Output the final values of all variables defined via the -var option. Multiple sets of “-ovar … -c …” can be specified. Only a single data row is output from each spec.

“-ovar[,AtrLst] File” sets the output attributes and file. See the aq_tool output specifications manual for details. In addition, the following attribute is supported:

    • fvar – Output to a dynamically defined target. File is the name of a previously defined string variable. The actual target file is obtained from the value of the variable. The initial value of the variable sets the initial file. Subsequently, when the value of the variable changes, the old output will be closed and the new one will be opened.

Optional “-c ColName [ColName …]” selects the variables to output. Normally, each selection is the name of a previously defined variable. In addition, these special forms are supported:

    • * – An asterisk adds all variables to the output.
    • ColName[:NewName][+NumPrintFormat] – Add ColName to the output. If :NewName is given, it will be used as the output label. The +NumPrintFormat spec is for numeric variables. It overrides the print format of the variable (be careful with this format – a wrong spec can crash the program).
    • ^ColName[:NewName][+NumPrintFormat] – Same as the above, but with a leading ^ mark. It is used to modify the output label and/or format of a previously selected output variable called ColName. If ^ColName[…] is the first selection after -c, then * will be included automatically first.
    • ~ColName – The leading ~ mark is used to exclude a previously selected output variable called ColName. If ~ColName is the first selection after -c, then * will be included automatically first.

If -o is given without a -c, then * is assumed.

Example:

$ aq_pp ... -d i:Col1 i:Col2 ... -var i:Sum1 0 -var i:Sum2 0 ...
-eval Sum1 'Sum1 + Col1' -eval Sum2 'Sum2 + (Col2 * Col2)' ...
-ovar - -c Sum1 Sum2
    • Calculate sums and output their values at the end of processing.

-imp[,AtrLst] DbName[:TabName] [-server AdrSpec [AdrSpec …]] [-local] [-mod ModSpec [ModSrc]]

Output data to Udb (i.e., perform an Udb import). DbName is the database name (see Target Udb Database). TabName is a table/vector name in the database. If TabName is not given or if it is a ”.” (a dot), a primary key-only import will be performed. Columns (including variables) from the current data set matching the column names of TabName are automatically selected for import. In case certain desired columns in the current data set are named differently from tbe columns of TabName, use -alias or -renam to remap their names manually.

Optional AtrLst is a comma separated list containing:

    • spec=UdbSpec – Set the spec file directly (see Target Udb Database).
    • ddef – Allow missing target columns. Normally, it is an error when a target column is missing from the current data set. With this attribute, 0 or blank will be used as the missing columns’ value.
    • nodelay – Send records to Udb servers as soon as possible. Otherwise, up to 16KB of data may be buffered before an output occurs.
    • seg=N1[-N2]/N[:V] – Only import a subset of the input data by selecting segment N1 or segments N1 to N2 (inclusive) out of N segments of unique keys based on their hash values. For example, seg=2-4/10 will divide the keys into 10 segments and import segments 2, 3 and 4; segments 1 and 5-10 are skipped. Optional V is a number that can be used to vary the sample selection. It is zero by default.
    • nobnk – Exclude records with a blank key from the import. This only applies with the primary key is made up of a single string column.
    • nonew – Tell the server not to create any new key during the import. In other words, records belonging to keys not yet in the DB are discarded.
    • noold – The opposite of nonew.

Optional “-server AdrSpec [AdrSpec …]” sets the target servers. If given, server spec in the Udb spec file will be ignored. AdrSpec has the form IP_or_Domain[|IP_or_Domain_Alt][:Port]. See Target Udb Database for details.

Optional “-local” tells the program to connect to the local servers only. Local servers are those in the server spec (from the Udb spec file or -server option) whose IP matches the the local IP of the machine the program is running on.

Optional “-mod ModSpec [ModSrc]” specifies a module to be loaded on the server side. ModSpec has the form ModName or ModName(Arg1, Arg2, …) where ModName is the module name and Arg* are module dependent arguments. Note that the arguments must be literals – string constants (quoted), numbers or IP addresses. ModSrc is an optional module source file containing:

    • A module script source file that can be used to build the specified module. See the Udb module script compiler documentation for more information.
    • A ready-to-use module object file. It must have a .so extension.

Without ModSrc, the server will look for a preinstalled module matching ModName.

Multiple sets of Udb import options can be specified.

Example:

$ aq_pp ... -d s:Col1 s:Col2 i:Col3 s:Col4 ... -imp mydb:Test
    • Import data set into Test.

Exit Status

If successful, the program exits with status 0. Otherwise, the program exits with a non-zero status code along error messages printed to stderr. Applicable exit codes are:

  • 0 – Successful.
  • 1 – Memory allocation error.
  • 2 – Command option spec error.
  • 3 – Initialization error.
  • 4 – System error.
  • 5 – Missing or invalid license.
  • 11 – Input open error.
  • 12 – Input read error.
  • 13 – Input processing error.
  • 21 – Output open error.
  • 22 – Output write error.
  • 31 – Udb connect error.
  • 32 – Udb communication error.
  • 33 – Udb authentication error.
  • 34 – Udb request invalid.

String Constant

A string constant must be quoted between double or single quotes. With double quotes, special character sequences can be used to represent special characters. With single quotes, no special sequence is recognized; in other words, a single quote cannot occur between single quotes.

Character sequences recognized between double quotes are:

  • \\ – represents a literal backslash character.
  • \” – represents a literal double quote character.
  • \b – represents a literal backspace character.
  • \f – represents a literal form feed character.
  • \n – represents a literal new line character.
  • \r – represents a literal carriage return character.
  • \t – represents a literal horizontal tab character.
  • \v – represents a literal vertical tab character.
  • \0 – represents a NULL character.
  • \xHH – represents a character whose HEX value is HH.
  • \<newline> – represents a line continuation sequence; both the backslash and the newline will be removed.

Sequences that are not recognized will be kept as-is.

Two or more quoted strings can be used back to back to form a single string. For example,

'a "b" c'" d 'e' f" => a "b" c d 'e' f

RT MapFrom Syntax

RT style MapFrom is used in both -mapf and -map options. The MapFrom spec is used to match and/or extract data from a string column’s value. It has this general syntax:

  • A literal – In other words, compare input data to a constant.
  • A literal and wild cards – literal_1%*literal_2%?literal_3 – %* matches any number of bytes and %? matches any 1 byte. This is like a pattern comparison.
  • A variable – %%my_var%% – Extract the value into a variable named my_var. my_var can later be used in the MapTo spec.
  • Literals and variables – literal_1%%my_var_1%%literal_2%%my_var_2%% – A common way to extract specific data portions.
  • Case sensitive or insensitive toggling – literal_1%=literal_2%=literal_3 – %= is used to toggle case sensitive/insensitive match. In the above case, if -mapf or -map does not have the ncas attribute, then literal_1‘s match will be case sensitive, but literal_2‘s will be case insensitive, and literal_3‘s will be case sensitive again.
  • ‘\’ escape – \%\%not_var\%\%%%my_var%%a_backslash\\others – If a ‘%’ is used in such a way that resembles an unintended MapFrom spec, the ‘%’ must be escaped. Literal ‘\’ must also be escaped. In summary, the following escape sequences are recognized:
    • \% – represents a literal percent character.
    • \\ – represents a literal backslash character.
    • \” – represents a literal double quote character.
    • \b – represents a literal backspace character.
    • \f – represents a literal form feed character.
    • \n – represents a literal new line character.
    • \r – represents a literal carriage return character.
    • \t – represents a literal horizontal tab character.
    • \v – represents a literal vertical tab character.
    • \0 – represents a NULL character.
    • \xHH – represents a character whose HEX value is HH.
    • \<newline> – represents a line continuation sequence; both the backslash and the newline will be removed.

Each %%var%% variable can have additional attributes. The general form of a variable spec is:

%%VarName[:@class][:[chars]][:min[-max]][,brks]%%

where

  • VarName is the variable name which can be used in MapTo. VarName can be a ‘*’; in this case, the extracted data is not stored, but the extraction attributes are still honored. Note: Do not use numbers as a RT mapping variable name.
  • :@class restricts the exctracted data to belong to a class of characters. class is a code with these values and meanings:
    • n – Characters 0-9.
    • a – Characters a-z.
    • b – Characters A-Z.
    • c – All printable ASCII characters.
    • x – The opposite of c above.
    • s – All whitespaces.
    • g – Characters in {}[]().
    • q – Single/double/back quotes.

Multiple classes can be used; e.g., %%my_var:@nab%% for all alphanumerics.

  • :[chars] ([] is part of the syntax) is similar to the character class described above except that the allowed characters are set explicitly. Note that ranges is not supported, all characters must be specified. For example, %%my_var:[0123456789abcdefABCDEF]%% (same as %%my_var:@n:[abcdefABCDEF]%%) for hex digits. To include a ‘]’ as one of the characters, put it first, as in %%my_var:[]xyz]%%.
  • :min[-max] is the min and optional max length (bytes, inclusive) to extract. Without a max, the default is unlimited (actually ~64Kb).
  • ,brks defines a list of characters at which extraction of the variable should stop. For example, %%my_var,,;:%% will extract data into my_var until one of ,;: or end-of-string is encountered. This usuage is often followed by a wild card, as in %%my_var,,;:%%%*.

RegEx MapFrom Syntax

Regular expression style MapFrom can be used in both -mapf and -map options. MapFrom defines what to match and/or extract from a string value of a column. Both the POSIX and PCRE (Perl Compatible regular expression) engines are supported. Which one to use depends on the mapping option’s attributes. See regular expression attributes for the appropriate attributes.

Differences between RegEx mapping and RT mapping:

  • RT pattern always matches the entire string, while RegEx pattern matches a substring by default. To get the same behavior, add ‘^’ and ‘$’ to the beginning and end of a RegEx as in ^pattern$.
  • The POSIX RegEx MapFrom does not have named variables for the extracted data. Instead, extracted data is put into implicit variables %%0%%, %%1%%, and so on. See -mapc for an usage example. The PCRE engine can optionally use named variables.
  • In addition to the standard regular expression escape sequences (\\, \+,\*, etc), the followings are also recognized:
    • \” – represents a literal double quote character.
    • \b – represents a literal backspace character.
    • \f – represents a literal form feed character.
    • \n – represents a literal new line character.
    • \r – represents a literal carriage return character.
    • \t – represents a literal horizontal tab character.
    • \v – represents a literal vertical tab character.
    • \0 – represents a NULL character.
    • \xHH – represents a character whose HEX value is HH.
    • \<newline> – represents a line continuation sequence; both the backslash and the newline will be removed.

Regular expression is very powerful but also complex. Please consult the POSIX or PCRE2 regular expression manuals for details.

MapTo Syntax

MapTo is used in -mapc and -map. It renders the data extracted by MapFrom into a column. Both RT and RegEx MapTo share the same syntax:

  • A literal – In other words, the result will be a constant.
  • A variable – %%my_var%% – Substitute the value of my_var.
  • Literals and variables – literal_1%%my_var_1%%literal_2%%my_var_2%% – A common way to render extracted data.
  • ‘\’ escape – \%\%not_var\%\%%%my_var%%a_backslash\\others – If a ‘%’ is used in such a way that resembles an unintended MapTo spec, the ‘%’ must be escaped. Literal ‘\’ must also be escaped. See RT MapFrom Syntax for all supported escape sequences.

Each %%var%% variable can have additional attributes. The general form of a variable spec is:

%%VarName[:cnv][[:start]:length][,brks]%%

where

  • VarName is the variable to substitute in.
  • :cnv sets a conversion method on the data in the variable. Note that the data is first subjected to the length and break considerations before the conversion. Supported conversions are:
    • b64 – Apply base64 decode.
    • url[Num] – Apply URL decode. Optional Num is a number between 1-99. It is the number of times to apply URL decode.
      Normally, only use 1 conversion. If both are specified (in any order), URL decode is always done before base64 decode.
  • :length (without a start position spec) is the number of bytes from the beginning of the extracted data to substitute. Default is till the end.
  • :start:length is the starting byte position and subsequent length of the extracted data to substitute. The first byte has position 0.
  • ,brks defines a list of characters at which substitution of the variable’s value should stop.

See -mapc for an usage example.

Target Udb Database

aq_pp obtains information about the target Udb database from a spec file. The spec file contains server IPs (or domain names) and table/vector definitions. See udb.spec for details. aq_pp finds the relevant spec file in several ways:

  • The spec file path is taken from the spec=UdbSpec attribute of the -imp or -exp option.
  • The spec file path is deduced implicitly from the DbName parameters of the -imp or -exp option. This method sets the spec file to “.conf/DbName.spec” in the runtime directory of aq_pp.
  • If none of the above information is given, the spec file is assumed to be “udb.spec” in the runtime directory of aq_pp.

Conditional Processing Groups

Some of the data processing options can be placed in conditional groups such that different processing rules can be applied depending on the logical result of another rule. The basic form of a conditional group is:

-if[not] RuleToCheck
RuleToRun
...
-elif[not] RuleToCheck
RuleToRun
...
-else
RuleToRun
...
-endif

Groups can be nested to form more complex conditions. Supported RuleToCheck and RuleToRun are -eval, -mapf, -mapc, -kenc, -kdec, -filt, -map, -sub, -grep, -cmb, -pmod, -o and -imp. Note that some of these rules may be responsible for the initialization of dynamically created columns. If such rules get skipped conditionally, numeric 0 or blank string will be assigned to the uninitialized columns.

There are 2 special RuleToCheck:

  • -true – Evaluate to true.
  • -false – Evaluate to false.

In addition, there are 3 special RuleToRun for output record disposition control (they do not change any data):

  • -skip – Do not output current row.
  • -quit – Stop processing entirely.
  • -quitafter – Stop processing after the current input record.

Example:

$ aq_pp ... -d i:Col1 ...
-if -filt 'Col1 == 1'
-eval s:Col2 '"Is-1"'
-elif -filt 'Col1 == 2'
-false
-else
-eval Col2 '"Others"'
-endif
...
  • Set Col2’s value based on Col1’s. In addition, discard any record with Col1==2.
$ aq_pp ... -d i:Col1 s:Col2 ...
-if -filt 'Col1 == 1'
-o Out1
-elif -filt 'Col1 == 2'
-o Out2 -c Col2
-endif
...

Output rows where Col1 equals 1 to Out1. Out1 will have all the input columns. Output rows where Col1 equals 2 to Out2. Out2 will have Col2 only. Rows with Col1 having other values are not output.

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