INPUT FROM statement

Specifies the new input source for a stream.

Syntax

INPUT [ STREAM stream | STREAM-HANDLE handle ] FROM
  {    opsys-file
     | opsys-device
     | TERMINAL
     | VALUE ( expression )
     | OS-DIR ( directory ) [ NO-ATTR-LIST ]
  }
  [ LOB-DIR { constant | VALUE ( expression ) } ] 
  [ BINARY ]
  [ ECHO | NO-ECHO ]
  [ MAP protermcap-entry | NO-MAP ]
  [ UNBUFFERED ]
  [     NO-CONVERT 
     | { CONVERT
            [ TARGET target-codepage ]
            [ SOURCE source-codepage ]
          }
  ]
STREAM stream
Specifies the name of a stream. If you do not name a stream, the AVM uses the unnamed stream. See the DEFINE STREAM statement reference entry and OpenEdge Development: Programming Interfaces for more information on streams.
STREAM-HANDLE handle
Specifies the handle to a stream. If handle it is not a valid handle to a stream, the AVM generates a run-time error. Note that stream handles are not valid for the unnamed streams. See the chapter on alternate I/O sources in OpenEdge Development: Programming Interfaces for more information on streams and stream handles.
opsys-file
The absolute or relative pathname of a file that contains the data you want to input. Any relative pathname is relative to the current working directory. Remember that UNIX file names are case sensitive. The pathname can contain Unicode characters. See OpenEdge Development: Internationalizing Applications for more information about Unicode.
opsys-device
The name of a UNIX or Windows device.
TERMINAL
Indicates that you want to get input from your terminal. The terminal is the default input source. You cannot use TERMINAL with STREAM.
VALUE ( expression )
An expression whose value is the source where you want to input data. The value can contain Unicode characters.
OS-DIR (directory)
Indicates that you want your input to be the filenames found in directory. The value of directory is a character expression specifying an operating system directory. This value can contain Unicode characters. If directory is not a directory or you do not have permission to read it, then the INPUT statement raises ERROR. Otherwise, the AVM generates the directory list and feeds it back to the calling program through the INPUT stream. An INPUT CLOSE statement discards any unread filenames from the list.

Each line read from the input stream is a string composed of three tokens: the file's base name, the file's absolute path name, and an attribute list indicating the file type, which consists of one or more of the characters listed below.

You will get one of the following characters:

  • F — Regular file or FIFO pipe
  • D — Directory
  • S — Special device
  • X — Unknown file type

You might also get one or more of the following characters:

  • H — Hidden file
  • L — Symbolic link
  • P — Pipe file

If you specify the NO-ATTR-LIST option, you will not get the attribute list for any line read from the input stream.

The two filenames in each input line are in EXPORT format; that is, they are enclosed in quotes and any embedded quotes are doubled. This means that INPUT FROM can process any filename, containing any characters, as long as IMPORT is used to read the input. The two filenames can use Unicode characters.

NO-ATTR-LIST

Omits the attribute list indicating the file type. This can speed up program execution. The following example illustrates this form of the statement:

INPUT FROM OS-DIR("c:\mydir") NO-ATTR-LIST.
LOB-DIR {constant| VALUE ( expression ) }
Specifies the directory from which you want the IMPORT statement to read large object data files (such as BLOB and CLOB data files). The constant and expression arguments are character expressions that evaluate to an absolute pathname or a relative pathname (relative to the directory specified for opsys-file).

If the specified character expression evaluates to either the Unknown value (?) or a directory that does not exist, or you do not have permission to read the specified directory, the AVM raises the ERROR condition.

The LOB-DIR option is valid only when you specify an operating system file as the input data source.

BINARY
Allows all input to be read directly without any conversion or interpretation. By default, NUL (\0) terminates character strings, and other control characters are interpreted as expected for the operating system.
ECHO
Displays all input data on the current output device. Data is echoed by default.
NO-ECHO
Accepts input data without displaying it on the current output device. If you do not use this option, INPUT FROM automatically displays input data on the current output device.
MAP protermcap-entry | NO-MAP
The protermcap-entry value is an entry from the PROTERMCAP file. Use MAP to read from an input stream that uses a different character translation from the current stream. Typically, protermcap-entry is a slash-separated combination of a standard device entry and one or more language-specific add-on entries (MAP laserwriter/french or MAP hp2/spanish/italian, for example). The AVM uses the PROTERMCAP entries to build a translation table for the stream. Use NO-MAP to make the AVM bypass character translation altogether. See OpenEdge Development: Internationalizing Applications for more information on PROTERMCAP and national language support.
UNBUFFERED
Reads one character at a time from a normally buffered data source, such as a file. Use the UNBUFFERED option only when you can intermingle the input operations of a UNIX process, invoked with the ABL UNIX statement, with the input that follows the ABL INPUT FROM statement.
CONVERT
Allows you to modify the character conversions occurring between the external file and ABL. By default, the INPUT FROM statement converts characters from the code page specified with the Stream Code Page (-cpstream) parameter to the code page specified with the Internal Code Page (-cpinternal) parameter. If you specify SOURCE source-codepage alone, the conversion accepts source-codepage as the code page name of the external file (instead of -cpstream). If you specify TARGET target-codepage, the conversion accepts target-codepage as the internal code page (instead of -cpinternal). If you specify both SOURCE source-codepage and TARGET target-codepage, it converts characters from the source-codepage to target-codepage (instead of -cpstream to -cpinternal).
TARGET target-codepage
Specifies the target code page of the character conversion (replacing -cpinternal). The name that you specify must be a valid code page name available in the DLC/convmap.cp file (a binary file that contains all of the tables that ABL uses for character management).
SOURCE target-codepage
Specifies the source code page of the character conversion (replacing -cpstream). The name that you specify must be a valid code page name available in the DLC/convmap.cp file (a binary file that contains all of the tables that ABL uses for character management).
NO-CONVERT
Specifies that no character conversions occur between the external file and memory. By default, the INPUT FROM statement converts characters from the -cpstream code page to the -cpinternal code page.

Example

Instead of getting input from the terminal, this procedure gets input from a file named r-in.dat. The SEARCH function determines the full pathname of this file.

r-in.p

INPUT FROM VALUE(SEARCH("r-in.dat")).

REPEAT:
  PROMPT-FOR Customer.CustNum Customer.CreditLimit.
  FIND Customer USING INPUT Customer.CustNum.
  ASSIGN Customer.CreditLimit.
END.

INPUT CLOSE.

This is what the contents of the r-in.dat file look like:

1 55800
2 41300
5 88000

The PROMPT-FOR statement uses the first data item (1) as the CustNum and the second data item (55800) as the CreditLimit. The FIND statement finds the customer whose CustNum is 1 and assigns the value of 55800 as that Customer's credit limit. On the next iteration of the REPEAT block, the PROMPT-FOR statement uses the value of 2 as the CustNum, the value of 41300 as the CreditLimit, etc.

The INPUT CLOSE statement closes the input source, resetting it to the terminal. When you run this procedure, the data in the window is simply an echo of the data that the procedure is reading from the taxno.dat file. If you do not want to display the data, add the word NO-ECHO to the end of the INPUT FROM statement.

Notes

See also

DEFINE STREAM statement, INPUT CLOSE statement, INPUT THROUGH statement, Stream object handle