Provided by: aegis_4.24.3-3_amd64 bug

NAME

        aer - aegis report script language definition

DESCRIPTION

        This manual entry describes the report generator script language used by the aer(1)
        command.  The language resembles C, with a touch of awk and perl for flavour.  It also
        closely resembles the appearance of aegis' database files.

        This language grew out of the need to have a general purpose programming language to
        describe reports, and yet be as familiar as possible to the people who will be using it.

WORDS AND SYMBOLS

        This section describes the various words and symbols understood by the language.

   Names
        A name is a contiguous set of alphanumeric characters, including underscore (_).  It must
        not start with a digit.  Names may be of any length.  Names are case sensitive, so
        uppercase and lowercase letters are unique.

        Here are some examples of names

                                     ┌─────────────────────────────┐
                                     │ print       sqrt       if   │
                                     │how_long   UpperCase   dig57 │
                                     └─────────────────────────────┘
        Some words are reserved as keywords.  These are the words which appear in bold in the
        statement descriptions, below.

   Integer Constants
        An integer constant may be decimal, any sequence of digits.  Constants may be octal, any
        sequence of octal digits starting with a zero.  Constant may be hexadecimal, any sequence
        of hexadecimal digits, starting with a 0x prefix.  These are represented by the internal
        long type, so significance is limited.

        Here are some examples of integer constants:

                                ┌───────────────────────────────────────┐
                                │        43            015       0xbeEf │
                                │2147483647   017777777777   0x7FFFFFFF │
                                └───────────────────────────────────────┘
   Floating Point Constants
        A floating point constant has an integer part, a fraction part and an exponent part.

        Here are some examples of floating point constants:

                                      ┌───────────────────────────┐
                                      │1.2e3   4.2e+1   1.628e-94 │
                                      │0.567      5e6         .67 │
                                      └───────────────────────────┘
   String Constants
        A string constant is represented as characters within double quotes (").  All characters
        in the script file are required to be printable, so special characters are represented by
        escape sequences.  These escape sequences are:

                                     ┌─────────────────────────────┐
                                     │\"     the " character       │
                                     │\\     the \ character       │
                                     │\n     Newline               │
                                     │\f     Form Feed             │
                                     │\r     Carriage Return       │
                                     │\b     Backspace             │
                                     │\t     Horizontal Tab        │
                                     │\nnn   octal character value │
                                     └─────────────────────────────┘
        Here are some examples of string constants:

                          ┌───────────────────────────────────────────────────┐
                          │"Hello, World!"     "Go away"            ""        │
                          │   "The End0      "slosh is \\"   "Say \"Please\"" │
                          └───────────────────────────────────────────────────┘
   Symbols
        The non-alphanumeric characters are used to represent symbols, usually expression
        operators or statement terminators.  The symbols used include:

                                       ┌──────────────────────────┐
                                       │ !    !=   !~    ##   ##= │
                                       │ %    %=    &    &&   &=  │
                                       │ (    )     *    **   **= │
                                       │*=    +    ++    +=    ,  │
                                       │ -    --   -=    .     /  │
                                       │/=    :     ;    <    <<  │
                                       │<<=   <=    =    ==    >  │
                                       │>=    >>   >>=   ?     [  │
                                       │ ]    ^    ^=    {     |  │
                                       │|=    ||    }    ~    ~~  │
                                       └──────────────────────────┘
   White Space
        White space serves to separate words and symbols, and has no other significance.  The
        language is free-form.  White space includes the SPACE, TAB, FF, and NEWLINE characters.

   Comments
        Comments are delimited by /* and */ pairs, and are treated as a single white space
        character.

STATEMENTS

        Statement serve to control the flow of execution of the program, or the existence of
        variables.

   The Expression Statement
        The commonest statement consists of an expression terminated by a semicolon.  The
        expression is evaluated, and any result is discarded.

        Examples of this statement include
                x = 42;
                print("Hello, World!0);

   The If Statement
        The if statement is used to conditionally execute portions of code.  Examples if the if
        statement include:
                if (x == 42)
                     x = 1;
                if (x * x < 1)
                     print("no");
                else
                     print("yes");

   The For Statement
        The for statement has two forms.  The first form is described as
                for (expr1; expr2; expr3)
                     stmt
        The expr1 is done before the loop begins.  The expr2 controls, the loop; if it does not
        evaluate to true the loop terminates.  The loop body is the stmt.  The loop increment is
        done by the expr3, and the the test is performed again.

        Each of the expressions is optional; any or all may be omitted.

        Here is an example of a for loop:
                for (j = 0; j < 10; ++j)
                     print(j);

        The second form of the for statement looks like this:
                for (name in keys(passwd))
                     print(name, passwd[name].pw_comment);

   The Break Statement
        The break statement is used to break out of a loop.

        Here is an example of a break statement:
                for (j = 0; ; j = 2 * j + 4)
                {
                     print(j);
                     if (j >= 0x800)
                          break;
                }
        The break statement works within all loop statements.

   The Continue Statement
        The continue statement is used to terminate the loop body and start another repetition.

        Here is an example of a continue statement:
                for (j = 0; j < 1000; j = 2 * j + 4)
                {
                     if (j < 42)
                          continue;
                     print(j);
                }
        The continue statement works within all loop statements.

   The While Statement
        The while statement is another loop construct.  The condition is evaluated before the
        loop body.
                line = 0;
                while (line < 7)
                {
                     print("");
                     ++line;
                }

   The Do Statement
        The do statement is another loop construct.  The condition is evaluate after the loop
        body.
                do
                     print("yuck");
                while
                     (line++ < 7);

   The Compound Statement
        The compound statement is a way of grouping other statements together.  It is enclosed in
        curly braces.
                if ( lines < 7)
                {
                     print("This\n");;
                     print("could\n");;
                     print("have\n");;
                     print("been\n");;
                     print("seven\n");;
                     print("blank\n");;
                     print("lines.\n");;
                }

   The Local Statement
        The auto statement is used to declare variables and initialize them to be nul.
                auto x, y, z;
                x = 42;
        All user-defined variables must be declared before they are used.

   The Null Statement
        The null statement does nothing.  It consists of a single semicolon.  It is most often
        seen as a loop body.
                for (n = 0, bit = 1; n < bit_num; ++n, bit <<= 1)
                     ;

   The Try Catch Statement
        The try catch statement is used to catch errors which would usually cause the report to
        fail.
                try
                     statement1
                catch (variable)
                     statement2
        The first statement is executed.  If no error occurs, nothing else is done.  If an error
        occurs in the execution of the first statement the firsdt statement execution is
        terminated and then the given variable is set to a description of the error and the
        second statement is executed.

EXPRESSIONS

        Expressions are much the same as in C, using the same operators.  The following table
        describes operator precedence and associativity:

        [ ]     subscripting                value [ expr ]
        ( )     function call               expr ( expr_list )
        ( )     grouping                    ( expr )

        ++      post increment              lvalue ++
        ++      pre increment               ++lvalue
        --      post decrement              lvalue --
        --      pre decrement               --lvalue
        ~       compliment                  ~ expr
        !       not                         ! expr
        -       unary minus                 - expr
        +       unary plus                  + expr

        **      exponentiation              expr ** expr

        *       multiply                    expr * expr
        /       divide                      expr / expr
        %       modulo (remainder)          expr % expr
        ~~      matches                     expr ~~ expr
        !~      does not match              expr !~ expr
        in      list member                 expr in expr

        +       addition (plus)             expr + expr
        -       subtraction (minus)         expr - expr
        ##      list and string join        expr ## expr

        <<      shift left                  expr << expr
        >>      shift right                 expr >> expr

        <       less than                   expr < expr
        <=      less than or equal          expr <= expr
        >       greater than                expr > expr
        >=      greater than or equal       expr >= expr

        ==      equal                       expr == expr
        !=      not equal                   expr != expr

        &       bitwise AND                 expr & expr

        ^       bitwise exclusive OR        expr ^ expr

        |       bitwise inclusive OR        expr | expr

        ? :     arithmetic if               expr ? expr : expr

        =       simple assignment           expr = expr
        *=      multiply and assign         expr *= expr
        /=      divide and assign           expr /= expr
        %=      modulo and assign           expr %= expr
        +=      add and assign              expr += expr
        -=      subtract and assign         expr -= expr
        <<=     shift left and assign       expr <<= expr
        >>=     shift right and assign      expr >>= expr
        &=      AND and assign              expr &= expr
        ^=      exclusive OR and assign     expr ^= expr
        |=      inclusive OR and assign     expr |= expr

        ,       comma (sequencing)          expr , expr

        Most of these operators behave as they do in C, but some of these operators will require
        some explanation.

   Exponentiation
        The ** operator raises the left argument to the right'th power.  It is right associative.

   Match
        The ~~ operator compares two strings.  It returns a number between 0.0 and 1.0.  Zero
        means completely different, one means identical.  Case is significant.

   Not Match
        The !~ is used to compare two strings, and returns the opposite of the ~~ operator; one
        if completely different, and zero if identical.

   String Join
        The ## operator is used to join two strings together.

TYPES

        There are several types used within the report language.

        array   Values of this type contain other values, indexed by a string.  If you attempt to
                index by an arithmetic type, it will be silently converted to a string.  Use the
                keys function to determine all of the keys; use the count function to determine
                how many entries an array has.  The type of an array element is not restricted,
                only the index must be a string.

        boolean This type has two values: true and false.  These value arise from the boolean
                operators described earlier.

        integer This type is represented by the long C type.  It has a limited range of values
                (usually -2e9 to 2e9 approximately).  If used in a string context, it will be
                silently converted to a string.  For exact control of the format, used the
                sprintf function.

        list    Values of this type contain a list of other values.  The type of these values is
                not restricted.  The array index operator (e[e]) may be used to access list
                elements; indexes start at zero (0).

        string  Values of this type are an arbitrary string of C characters, except the NUL
                character ( ).  Strings may be of any length.

        struct  Values of this type contain additional values.  These values are accessed using
                the "dot" operator.  These values may also be treated as if they were arrays.

        real    This type is represented the the double C type.  If used in a string context, it
                will be silently converted to a string.  For exact control of the format, used
                the sprintf function.

FUNCTIONS

        There are a number of built-in functions.

        basename
                This function is used to extract the last element from a file path.

        capitalize
                This function converts it argument to a capitalized string in Title Case.

        ceil    This function is used to round a number to an integer, towards positive infinity.

        change_number
                This function is used to determine the change number.  It may be set by the
                -Change command line option, or it may default.  The return value is an integer.

        change_number_set
                This function maybe used to determine if the change number was set by the -Change
                command line option.  The return value is a boolean.

        columns This function is used to define the report columns.  Each argument is a structure
                containing some or all of the following fields:

                               left      the left margin, counting characters
                                         from 0 on the left
                               right     the right margin, plus one
                               width     the width in characters, defaults to 7
                                         if right not specified
                               padding   white space between columns, defaults to
                                         1 if not set
                               title     the title for this column, separate
                                         multiple lines with \n
                The columns must be defined before the print function is used.

        count   This function is used to count the number of elements in a list or array.

        dirname This function is used to extract all but the last element from a file path.

        downcase
                This functions converts its argument to lower case.

        eject   This function is used to start a new page of output.

        floor   This function is used to round a number to an integer, towards negative infinity.

        getenv  This function is used to get the value of an environment variable.  Will return
                the empty string if not set.

        gettime This function is used to parse a string to produce a time.  It understands a
                variety of different date formats.

        getuid  This function takes no arguments, and returns the user ID of the process which
                invoked the report generator. The return value is an integer.

        keys    This function may be given an array or a list as argument.  It returns a list of
                keys which may be used to index the argument.  Most often seen in for loops.

        length  This function is used to find the length of a string.

        mktime  This a synonym for the gettime function.

        mtime   This function may be used to obtain the modification time of a file.

        need    This function is used to insert a page break into the report if the required
                number of lines is not available before the end of page.  If sufficient lines are
                available, only a single blank line will be inserted.  The return value is void.

        now     This function takes no arguments, and returns the current time.

        page_length
                This function may be used to determine the length of the output page in lines.
                The return value is an integer.

        page_width
                This function may be used to determine the width of the output page in columns.
                The return value is an integer.

        print   This function is used to print into the defined columns.  Columns will wrap
                around.

        project_name
                This function is used to determine the project name.  It may be set by the
                -Project command line option, or it may default.  The return value is a string.

        project_name_set
                This function maybe used to determine if the project name was set by the -Project
                command line option.  The return value is a boolean.

        quote_html
                This function quotes its argument string to insulate HTML special characters;
                these include “less than” (<), “ampersand” (&) and non-printing characters.  This
                is most often used to generate suitable text for web pages.

        quote_tcl
                This function quotes its argument string to insulate TCL special characters;
                these include “[]” and non-printing characters.  This is most often used to
                generate suitable text for TCL interface scripts.

        quote_url
                This function quotes its argument string to insulate URL special characters;
                these include “?+#:&=” and non-printing characters.  This is most often used to
                generate suitable text for web pages.

        round   This function is used to round a number to an integer, towards the closest
                integer.

        sort    This function must be given a list as argument.  The values are sorted into
                ascending order.  A new list is returned.

        split   This function is used to split a string into a list of strings.  The first
                argument is the string to split, the second argument is the character to split
                around.

        sprintf This function is used to build strings.  It is similar to the sprintf(3)
                function.

        strftime
                This function is used to format times as strings.  The first argument is the
                format string, the second argument is a time.  See the strftime(3) man page for
                more the format specifiers.

        subst   This function is used to substitute strings by regular expression.  The first
                argument is the pattern to match, the second argument is the substitution
                pattern, the third argument is the input string to be substituted.  The option
                fourth argument is the number of substitutions to perform; the default is as many
                as possible.

        substr  This function is used to extract substrings from strings.  The first argument is
                a string, the second argument is the starting position, starting from 0, and the
                third argument is the length.

        terse   This function may be used to determine of the -TERse command line option was
                used.  The return type is a boolean.

        title   This function is used to set the title of the report.  It takes at most two
                arguments, one for each available title line.

        trunc   This function is used to round a number to an integer, towards zero.

        typeof  This function is used to determine the type of a value.  The return type is a
                string containing the name of the type, as described in the

        unquote_url
                This function will remove URL quoting from the argument string.  URL quoting
                takes the form of a percent sign (%) followed by two hex digits.  This is
                replaced by a single character with the value represented by the hex digits.

        upcase  This functions converts its argument to upper case.

        working_days
                This function is used to determine the number of working days between two times.

        wrap    This function is used to wrap a string into a list of strings.  The first
                argument is the wring to wrap, the second argument is the maxmium width of the
                output strings.

        wrap_html
                This function is used to wrap a string into a list of strings.  The first
                argument is the wring to wrap, the second argument is the maxmium width of the
                output strings.  This is very similar to the wrap functions, except thatit
                inserts HTML paragraph breaks <p> or line breaks <br> to reflect the newlines
                within the string (2 or 1, respectively).  TYPES section.

VARIABLES

        There are a number of built-in variables.

        arg     This variable is a list containing the arguments passed on the aer(1) command
                line.

        change
                There is a special type of variable created by using an expression similar to
                project[project_name()].state.change[n] which contains all of the fields
                described in aecstate(5), plus some extras:

                change  Branches have a change array, just like project below.

                change_number
                        The number of the change.

                config  This gives access to all of the fields described in aepconf(5).

                project_name
                        The name of the project containing the change.

                src     This gives access to the change files, and when indexed by file name,
                        yields a value conataining fields as described in aefstate(5), for the
                        src field.

        group   This variable is an array containing all of the entries in the /etc/group file.
                Each entry is a structure with fields as documented in the group(5) manual entry.
                The gr_mem element is a list of strings.  This array may be indexed by either a
                string, treated as a group name, or by an integer, treated as a GID.

        passwd  This variable is an array containing all of the entries in the /etc/passwd file.
                Each entry is a structure with fields as documented in the passwd(5) manual
                entry.  This array may be indexed by either a string, treated as a user name, or
                by an integer, treated as a uid.

        project This variable is an array containing one entry for each aegis project, indexed by
                name.  Each array element is a structure, containing

                               name        the project name
                               directory   the root of the project directory tree
                               state       the project state
                The project state contains the fields documented in the aepstate(5) manual entry.
                Except: the change field is not a list of change numbers, it is an array indexed
                by change number of change states, as documented in the aecstate(5) manual entry.
                (See change, above.)

        user    This variable is an array containing the .aegisrc file of each user.  Each entry
                is a structure with fields as documented in the aeuconf(5) manual entry.  This
                array may be indexed by either a string, treated as a user name, or by an
                integer, treated as a uid.  Files which are unreadable or absent will generate an
                error, so you need to wrap accesses in a try/catch statement.  (Note: count() and
                keys() functions think the array is empty; if you want a list of users, consult
                the passwd array.)

FILES

        The reports are kept in the /usr/share/aegis/report directory.  The reports are
        associated with a name by the /usr/share/aegis/report.index file.  Their names use the
        command line argument abbreviation scheme, so that report names may be abbreviated.

SEE ALSO

        aer(1)  report generator

        aecstate(5)
                change state description

        aepstate(5)
                project state description

        aerptidx(5)
                report index file format

COPYRIGHT

        aegis version 4.24.3.D001
        Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
        2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Peter Miller

        The aegis program comes with ABSOLUTELY NO WARRANTY; for details use the 'aegis -VERSion
        License' command.  This is free software and you are welcome to redistribute it under
        certain conditions; for details use the 'aegis -VERSion License' command.

AUTHOR

        Peter Miller   E-Mail:   millerp@canb.auug.org.au
        /\/\*             WWW:   http://www.canb.auug.org.au/~millerp/