Using gpre
Go Up to Preprocessing
The syntax for gpre
is:
gpre [-language] [-options] infile [outfile]
The infile
argument specifies the name of the input file.
The optional outfile
argument specifies the name of the output file. If no file is specified, gpre
sends its output to a file with the same name as the input file, with an extension depending on the language of the input file.
gpre
has switches that allow you to specify the language of the source program and a number of other options. You can place the switches either before or after the input and output file specification. Each switch must include at least a hyphen preceded by a space and a unique character specifying the switch.
Language Switches
The language switch specifies the language of the source program. C and C++ are languages available on all platforms. The switches are shown in the following table:
Switch | Language |
---|---|
-c |
C |
-cxx |
C++ |
In addition, some platforms support other languages if an additional InterBase license for the language is purchased. The following table lists the available languages and the corresponding switches:
Switch | Language |
---|---|
-al[sys] |
Ada (Alsys) |
-a[da] |
Ada (VERDIX, VMS, Telesoft) |
-ansi |
ANSI-85 COBOL |
-co[bol] |
COBOL |
-f[ortran] |
FORTRAN |
-pa[scal] |
Pascal |
For example, to preprocess a C program called census.e
, type:
gpre -c census.e
Option Switches
The option switches specify preprocessing options. The following table describes the available switches:
Switch | Description |
---|---|
-charset <name> |
Determines the active character set at compile time, where <name> is the character set name. |
-d[atabase] <filename> |
Declares a database for programs. <filename> is the file name of the database to access. Use this option if a program contains SQL statements and does not attach to the database itself. Do not use this option if the program includes a database declaration. |
-d_float |
VAX/VMS only. Specifies that double-precision data will be passed from the application in D_FLOAT format and stored in the database in G_FLOAT format. Data comparisons within the database will be performed in G_FLOAT format. Data returned to the application from the database will be in D_FLOAT format. |
-e[ither_case] |
Enables |
-m[anual] |
Suppresses the automatic generation of transactions. Use the |
-n[o_lines] |
Suppresses line numbers for C programs. |
-o[utput] |
Directs the output of |
-password <password> |
Specifies <password>, the database password, if the program connects to a database that requires one. |
-r[aw] |
Prints BLR as raw numbers, rather than as their mnemonic equivalents. This option can be useful for making the |
-sql_dialect |
Sets the SQL dialect. Valid values are 1, 2, and 3. |
-user <username> |
Specifies <username>, the database user name, if the program connects to a database that requires one. |
-x <handle> |
Gives the database handle identified with the |
-z |
Prints the version number of |
For sites with the appropriate license and are using a language other than C, additional gpre
options can be specified, as described in the following table:
Switch | Description |
---|---|
-h[andles] <pkg> |
Specifies, <pkg>, an Ada handles package. |
Examples of Using gpre
The following command preprocesses a C program in a file named appl1.e
. The output file will be appl1.c
. Since no database is specified, the source code must connect to the database.
gpre -c appl1
The following command is the same as the previous, except that it does not assume the source code opens a database, instead, explicitly declaring the database, mydb.ib
:
gpre -c appl1 -d mydb.ib