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THE SCRIPT LANGUAGE The script language interpreted by "Terminal" is a subset of C with many specialized intrinsic (built-in) functions. Please read a C reference book to learn the C syntax, or see the enclosed script examples to get a feeling of the language. I will not write a book about programming in C here, only tell you the essentials. PROGRAM A program is recognized as a script if it is in a TEXT file, and if the file name ends in ".s". Spaces, tabs and carriage return characters are considered to be white space. No identifier and no keyword can be separated by white space. A program consists of: comments, global variable definitions and function definitions. Everything included between "/*" and "*/" is considered a comment and will not be interpreted. Comments cannot be nested. The "/*" and "*/" are not recognized as comment delimiters inside string or character constants. Global variables are those variables that are known to all functions, unless their names are reused as local variables. Global variables can be initialized using any expression that involves either constants or other globals that are already defined at that point. Function definitions can appear in any order and their must be at least one function called "main" with no parameters. It is this function that is called when the script is started. Every function is supposed to return an integer value as result. If there is no return statement in a function, 0 will be returned. Functions can be called recursively. There are many built-in functions that are already defined when the script is started. The value the "main" function returns is used as follows: 0 : Don't restore saved settings, continue application 1 : Restore saved settings, continue application 256 : Don't restore saved settings, quit application 257 : Restore saved settings, quit application Restore saved settings means that all changes the script made to settings are forgotten as soon as the script finishes. Quit application means, that as soon as the script has finished, "Terminal" quits. Usually this means returning to the Finder. But if "Terminal" was launched from HyperCard it will return to HyperCard. This is an example of a simple script that displays the message "The number is 123" in the terminal window: int Number = 123; /* This is a global variable */ main () /* Every script must have a main() function */ { /* display() is a built-in function */ display("The number is %i\r", Number); } IDENTIFIERS An identifier is a sequence of letters and digits; the first character must be a letter. The underscore "_" counts as a letter. An identifier can be of any length up to 255 characters. All characters are significant and are case sensitive. There are three types of identifiers: keywords, function names, variable names. The keywords are: "break", "char", "else", "for", "if", "int", "return", "while". CONSTANTS An integer constant is a sequence of decimal digits, or 0x followed by up to 8 hexadecimal digits. An integer value is represented internally by 4 bytes (32 bits). A minus sign before a constant is considered as an unary operator, not a part of the constant itself. A character constant is a sequence of 1 to 4 characters enclosed in single quotes. Character constants are converted to integer values, the byte values corresponding to the ASCII codes of the characters. A string constant is a sequence of characters enclosed in double quotes. String constants are automatically terminated by a NULL character. The value of a string constant is the address of the first character. Some examples of valid constants: 1234567 0xABCD1234 'a' 'TEXT' "An apple a day keeps troubles away" In character and string constants the backslash "\" is used as an escape sequence according to the following table: LF 0x0A \n TAB 0x09 \t FF 0x0C \f BELL 0x07 \a BS 0x08 \b CR 0x0D \r VT 0x0B \v NULL 0x00 \0 any 0x.. \x.. (2 hex digits) If the character following a backslash is not one of those specified the backslash is ignored. This can be used to represent the backslash itself, to put a single quote into a character constant or to put a double quote into a string constant. Some examples; "Going to the next line...\r" '\0' "This is a single backslash: \\" "\"Hello world!\"" '\'' '\x03' /* That's a control-C */ VARIABLES There are four types of variables: characters, integers, pointers and arrays. Integers represent 32 bit signed values and characters 8 bit signed values. Pointers hold the 32 bit address of integers, characters or other pointers. Arrays are more or less equivalent to pointers. The following examples show how variables are defined: char c; /* "c" is a character variable */ int n; /* "n" is an integer variable */ char *ptr; /* "ptr" is a pointer to characters */ char **hdl; /* "hdl" is a pointer to character pointers */ int *p; /* "p" is a pointer to integers */ int **q; /* "q" is a pointer to integer pointers */ char a[80]; /* "a" points to an array of 80 characters (80 bytes) */ int b[10]; /* "b" points to an array of 10 integers (40 bytes) */ char *c[5]; /* "c" points to an array of 5 character pointers (20 b) */ int *d[5]; /* "d" points to an array of 5 integer pointers (20 b) */ Variable declarations can be grouped together like this: char c, *ptr, **hdl, a[80], *c[5]; int n, *p, **q, b[10], *d[5]; Variables can be initialized using any legal expression, not only constants. Arrays can only be initialized at the global level, i.e. outside of function definitions. Initialized arrays must not include their size between the square brackets, the size is calculated based on the initializing values. char c = 'x'; int n = -123; int m = n * 10; /* "m" is set to -1230 */ char message[] = "This is a character string"; char *messages[] = /* Array of strings */ { "This is string #1", "Another string", "and so on..." }; int a[] = { 1, 2, 3, 4, 5 }; /* Array of 5 integers */ The are no logical variables. Everything that is not zero is considered to be true. EXPRESSIONS The following is a list of the supported operators that build up an expression. The list is by increasing precedence. Normally operators group left to right unless otherwise noted below. Note that the assignment is an operator, that an expression may contain several assignments, and that an assignment returns a value. Logical and numerical operators can be freely mixed, everything not zero is considered to be true. The precedence level can be changed by using parentheses. The boolean operators will return 1 as true. Assignment = (right to left) Logical or || Logical and && Equal, not equal == != Relational operators < <= > >= Add, subtract + - Multiply, divide, modulo * / % Logical not, increment, decrement, unary minus, indirection, address of ! ++ -- - * & (right to left) Function call, array element () [] The increment or decrement operators can be used before or after a variable. If the operator comes before the variable (preincrement, predecrement) the variable is incremented, or decremented, and then the variable's value is used in the expression evaluation. If the operator comes after the variable (postincrement, postdecrement) the current value of the variable is used in the expression evaluation, and then the variable is incremented, or decremented. Array subscripts start with 0. There is no runtime check of array boundaries. An array subscript can be any valid expression. Some examples: char a[80]; c = a[0]; /* The first element */ c = a[79]; /* The last element */ c = a[i = (79 - Func(x)*3)]; /* Expression as subscript */ For pointer arithmetic the following rules apply: if an integer value is added or subtracted from a pointer (a pointer is an address) then the integer value is first scaled depending on what the pointer is pointing to: 1 for characters, 4 for integers, 4 for pointers. If two pointers are subtracted the result is scaled in the same way and yields an integer value representing the number of objects separated by the two pointers. The two pointers must point to the same type of objects. A function identifier without a parameter list in an expression results in the address of the function being used. If there is a parameter list, the function is called and the integer value returned by the function is used. Functions can also be called indirectly, using any expression that yields a valid function address followed by a parameter list. Some examples: int pf; /* "int" can be used as function pointer */ int i; pf = Func; /* "pf" will contain address of function "Func" */ i = Func(); /* "i" gets function result */ i = (pf)(); /* "i" gets function result */ FUNCTIONS A function definition can only occur in the outer, global level. A function cannot be defined inside another function. All functions are supposed to return integers. A function definition consists of the function name, followed by a parameter definition list enclosed in parentheses, followed by a compound statement. The parameter definition list describes the function parameters. These parameters are considered as local variables inside the function. Example: /* The following function takes 3 parameters: a character, an integer and a character pointer. It always returns the value 123. */ Function (char c, int i, char *p) { /* ... */ return 123; } A function call consists of the function name followed by a parameter list. The parameter list is a comma separated list enclosed in parentheses of expressions. All parameters are passed by value. There is no verification if the number of parameters is correct or if the values passed to a function correspond to the types of the declared parameters. Example: i = Function ('x', 4567 + x, "Hello"); STATEMENTS A compound statement starts with an open brace "{" and terminates with a closing brace "}". There is an optional variable definition part followed by a list of statements. Variables defined inside a compound statement are local to that compound statement (block). A statement can be: compound statement expression ; if ( expression ) statement if ( expression ) statement else statement while ( expression ) statement for ( opt expr1 ; opt expr2 ; opt expr3 ) statement break ; return ; return expression ; ; The two forms of the conditional statement are: if ( expression ) statement if ( expression ) statement else statement In both cases the expression is evaluated and if it is nonzero, the first substatement is executed. In the second case the second substatement is executed if the expression is 0. The "else" ambiguity is resolved by connected an "else" with the last encountered "else"-less "if". The "while" statement has the form: while ( expression ) statement The substatement is executed repeatedly so long as the value of the expression remains nonzero. The test takes place before each execution of the statement. The "for" statement has the form: for ( opt expr1 ; opt expr2 ; opt expr3 ) statement This statement is equivalent to: expression1 ; while ( expression2 ) { statement expression3; } Thus the first expression specifies initialization for the loop, the second specifies a test, made before each iteration, such that the loop is exited when the expression becomes 0; the third expression often specifies an incrementation which is performed after each iteration. Any or all of the expressions may be dropped. A missing expression2 makes the implied "while" clause equivalent to while(1); other missing expressions are simply dropped from the expansion above. The statement break ; causes termination of the smallest enclosing "while" or "for" statement; control passes to the statement following the terminating statement. A function returns to its caller by means of the "return" statement, which has one of the forms: return ; return expression ; In the first case the returned value is undefined. In the second case the value of the expression is returned to the caller of the function. If required, the expression is converted to an integer. Flowing off the end of a function is equivalent to a return with no return value. The null statement has the form ; A null statement is useful to supply a null body to a looping statement such as "while". Note: Unlike real C, logical expressions are completely evaluated, even if their TRUEthness (different from 0) ore FALSEness (equal to 0) can be determined before the whole expression is evaluated. In real C that's called short circuit boolean evaluation. For example in the statement if (dothis() && dothat()) ; the functions dothis() and dothat() are always called in script C. In real C the function dothat() is only called if dothis() returns a non-zero result. ___________________________________________________________________________ INTRINSIC FUNCTIONS Intrinsic functions are built-in and need not to be defined in the script. They can be called by any script. All file access functions operate on the file transfer up- and download folder, which is the folder that can be set with the "Binary file transfer options..." menu item. File names can be up to 31 characters long and cannot contain the character ':'. All formatting functions ("display", "format", "type") use a template string to specify the formatting to be done on the following parameters. Format specifiers begin with the character % and include zero or more of the following conversion specification elements (optional fields are in brackets): % [option flags] [field size] conversion Some of these elements are optional, but if present, they must be specified in the order in which they are described below. Option flags (optional): - Left adjust output in field, pad on right (default is to right justify). 0 Use zero (0) rather than space for the pad character Field size specification (optional): The minimum field width, expressed as a decimal integer. The corresponding parameter will be printed in a field at least this wide. Conversion characters (required) c Parameter is a character i Parameter is an integer s Parameter is a null terminated string % Print a %, no parameter used The format specification elements must correspond to the following parameters. Some examples: char k, m[80]; int n; type("Unrecognized character %c on line %i of file %s\r", k, n, m); The following list describes all the existing intrinsic functions. They are described in the so-called prototype format, i.e. the format you would have to use to define them. E.g. xxxx (char *s, int i) means that "xxxx" is a function taking 2 arguments, the first is a pointer to a character and the second is an integer. Note that all functions return integers, but the value returned is not necessarily meaningful for very function. autolf Set the auto linefeed flag on or off autolf (int flg) flg: 0 means off, 1 means on beep Macintosh system beep beep () capture Start/stop capture to text file capture (int opt, char *name) result: Macintosh file system error, 0 if no error opt: 0 = Close capture file 1 = Capture on, new file 2 = Capture on, append to existing file name: Pointer to character string of at least 32 characters. This is the file name. catalog Return file info catalog (int i, char *name, int *type, int *dsize, int *rsize, int *cdate, int *mdate) result: Macintosh file system error, 0 if no error i: If 0, then name must be specified and information about the file with that name is returned, if it exists. If non-zero information (including file name) about the i-th file in the folder is returned. name: Pointer to character string of at least 32 characters. This is the file name (specified or returned depending on the value of i). type: Integer (4 bytes). File type. dsize: Data fork size in bytes. rsize: Resource fork size in bytes. cdate: Creation date in seconds. mdate: Modification date in seconds. date Convert seconds from Macintosh clock to date and time date (int sec, int *yr, int *mo, int *da, int *ho, int *mi, int *se, int *dw) sec: Seconds yr: Year (1904..20xx) mo: Month (1..12) da: Day (1..31) ho: Hour (0..23) mi: Minutes (0..59) se: Seconds (0..59) dw: Day of week (1..7, Sunday is 1) display Display in the terminal window display (char *templ, ...) templ: Template string ...: Variable number of arguments (maximum 9) download Download (receive) a binary file using X/Y/Z-Modem protocol download (char *name, int bin, int zmodem) result: Error code. 0 if Ok. 1 if timeout. 2 if cancel. 3 if abort (5 consecutive control-X characters received). All other values are Macintosh file system errors. name: File name for new file (not used for Y-Modem batch or Z-Modem) bin: 1 to recognize and use MacBinary format zmodem: 0 use X/Y-Modem, 1 use Z-Modem format Formatted conversion of values into a string format (char *str, char *templ, ...) str: String for result templ: Template string ...: Variable number of arguments (maximum 8) free Dispose of the memory allocated by the new() function free (char *p) p: Pointer returned by previous call to new() function getcts Get current state of CTS input line getcts () result: 0 if negated, 1 if asserted getdcd Get current state of DCD input line getdcd () result: 0 if negated, 1 if asserted lecho Set the local echo flag on or off lecho (int flg) flg: 0 means off, 1 means on macrol Load new macros file macrol (char *name) result: Error code, 0 means no error name: File name of TEXT file with macros (folder will be the same as the "Terminal folder") macrox Execute macro macrox (int i, int op, char *name) result: Error code, 0 ok, 2 cancel, 3 abort (2 consecutive control-X characters received) i: Macro number (0 to 9) op: 0 send macro text (using send TEXT file parameters), 1 display macro text, 2 return macro name name: Only used if op is 2, should point to a string where macro name will be returned (at least 30 characters long) move Move bytes from source to destination move (char *src, char *dest, int cnt) src: Source pointer dest: destination pointer cnt: number of bytes to move new Allocate memory new (int size) result: Pointer to memory, or 0 if not enough memory available size: Number of bytes to allocate nextbuff Wait for some characters nextbuff (char *buff, int count, int t) result: count characters received, 1 timeout, 2 cancel, 3 abort (5 consecutive control-X characters received) count: Number of characters to wait for buff: Character buffer to hold received characters. Must be at least count characters long t: Timeout value in ticks (1/60th of second) nextline Wait for the next line received over the serial input port nextline (char *line, int t) result: 0 line received, 1 timeout, 2 cancel, 3 abort (5 consecutive control-X characters received) line: String to hold line, this will be a '\0' terminated string without the final carriage return t: Timeout value in ticks (1/60th of second) pause Pause for specified amount of time pause (int t) result: 1 timeout, 2 cancel. t: Timeout value in ticks (1/60th of second) prompt Wait for a prompt string to come over the serial input port prompt (char *str, int t) err: 0 string received, 1 timeout, 2 cancel, 3 abort (5 consecutive control-X characters received). str: String to wait for (case sensitive) t: Timeout value in ticks (1/60th of second) protocol Set binary file transfer options protocol (bin, qb, zmodem, autorx) bin: 0 no MacBinary, 1 use MacBinary, -1 no change qb: 0 no QuickB, 1 use QuickB, -1 no change zmodem: 0 Z/Y-Modem, 1 Z-Modem, -1 no change autorx: 0 no auto-receive, 1 Z-Modem auto-receive, -1 no change recho Set the remote echo flag on or off recho (int flg) flg: 0 means off, 1 means on save Set the save & display flag on or off save (int flg) flg: 0 means off, 1 means on send Send a text file over the serial output port send (char *name) result: error code. 0 if Ok. 2 if cancel. 3 abort (5 consecutive control-X characters received). All other values are Macintosh file system errors. name: File name setdtr Set DTR output line setdtr (int onoff) onoff: 0 to negate, 1 to assert setup Serial communications port setup setup (int baud, int data, int parity, int stop, char *port, int dtr, int hs) result: 0 if no error baud: 0=300, 1=600, 2=1200, 3=2400, 4=4800, 5=9600, 6=19200, 7=38400, 8=57600 baud (or -1 for no change) data: 0=7, 1=8 data bits (or -1 for no change) parity: 0=no, 1=even, 2=odd parity (or -1 for no change) stop: 0=1, 1=2 stop bit (or -1 for no change) port: port's name, e.g. "Modem Port" or "Printer Port" (or -1 for no change) dtr: 1=don't drop DTR when quitting (or -1 for no change) hs: Handshake 0=none, 1=XON/XOFF, 2=CTS, 3=DTR, 4=CTS/DTR stack Return free memory available for script heap and stack stack () result: Combined free heap and stack space (bytes) strcmp Compare two strings (not case sensitive) strcmp (char *str1, char *str2) result: 0 if strings are equal, positive if str1 > str2, negative if str1 < str2 str1: First string str2: Second string terminal Set terminal parameters terminal (int lecho, int recho, int autolf, int save) lecho: Local echo flag (or -1 if no modification) recho: Remote echo flag (or -1 if no modification) autolf: Auto line feed flag (or -1 if no modification) save: Save & capture flag (or -1 if no modification) text Set text file send parameters text (char *prompt, int lined, int chard) prompt: Prompt text lined: Ticks to wait after each line chard: Ticks to wait after each character time Return seconds from Macintosh clock time () result: Seconds type Send a string over the serial output port type (char *templ, ...) templ: Template string ...: Variable number of arguments (maximum 9) upload Upload (transmit) a binary file using X/Y/Z-Modem protocol upload (char *name, int bin, int zmodem) result: error code. 0 if Ok. 1 if timeout. 2 if cancel. 3 abort (5 consecutive control-X characters received). All other values are Macintosh file system errors. name: File name bin: 1 to recognize and use MacBinary format zmodem: 0 use X/Y-Modem, 1 use Z-Modem val Convert string to number val (char *str) result: Converted integer value str: Character string (0 terminated) xyparms Set binary file transfer options for X/Y-Modem xyparms (crc, k, batch, t) crc: 0 use checksum, 1 use CRC, -1 no change k: 0 use 128 Byte blocks, 1 use 1 KByte blocks "C", 2 use 1 KByte blocks "CK", -1 no change batch: 0 no batch (X-Modem), 1 batch official (Y-Modem), 2 batch RR (Y Modem), -1 no change t: timeout to use in ticks, -1 no change zparms Set binary file transfer options for Z-Modem zparms (ctl, t, retr, buf, pack, wind, crcq) ctl: 0 don't escape control characters, 1 escape control characters, -1 no change t: timeout to use in ticks, -1 no change retr: maximal retry count, -1 no change buf: receive buffer size in bytes, -1 no change pack: transmit sub-packet length in bytes, -1 no change wind: transmit window size in bytes, -1 no change crcq: transmit ZCRCQ spacing in bytes, -1 no change