【 Weak current College 】 DOS command in Visual FoxPro (7)

(6) ATTRIB-modify file properties command

1. function: modify the properties of the specified file. (File properties see 2.5.4 (2) the file properties section)

2. type: external commands.

3. format: ATTRIB [filename] [R] [-R] [A] [-A] [H] [-H] [S] [-S] [/S]

4. instructions for use:

(1) choose the R parameter, the specified file as read-only property, so the files can only be read, can't write data or remove; selection-R parameter to remove the read-only property;

(2) select A parameter and sets the file attributes for the file; select — A parameter that removing files properties;

(3) choose the H parameter, the file transfer protocol to suppress attribute; selection — H parameter to suppress the property;

(4) the selection of the S parameter, the file is set to system properties; selection-S parameter to remove the system attribute;

(5) selection of the/s parameter to the current directory and all subdirectories.

7) DEL: delete file command

1. function: delete the specified file.

2. type: internal commands

3. format: DEL [drive:] [path] page〈 filename >

4. instructions for use:

(1) choose the/P parameter, the system asks whether you want to delete before you really want to delete the file, if you do not use this parameter, you automatically delete;

(2) this command does not delete the attribute to suppress or read-only files;

(3) in the file name you can use a wildcard character;

(4) If you want to delete all the files on the disk (DEL * · * or DEL ·), you will be prompted: (Areyousure?) (are you sure?) to answer Y, you remove it, answer n, then cancel the delete operation.

(8) UNDELETE-recover delete command

1. function: restore mistakenly deleted command

2. type: external commands.

3. format: UNDELETE [drive:] [path name] page〈 filename > [/DOS]/LIST] [/ALL]

4. instructions for use: use UNDELETE can use "*" and "?" wildcards.

(1) selection parameters according to the directory where/DOS residual records to recover the files. Because the file is deleted, the directory is first recorded Tsam filename characters will be converted to DOS that is based on the E5, the beginning of a file and its subsequent E5 to locate a file to recover, UNDELETE, therefore, will require the user to enter a character, to complement the file name. But the characters do not have to and original, just need to conform to the DOS filename rules.

(2) choose "listed"/LIST only that meets the specified criteria of a file without recovery, disk content will not be affected.

(3) use will automatically complete/ALL recovered files full restoration, not a one to ask the user, use this parameter when you use directory UNDELTE residual records to recover the files, you will automatically select a character name complement, and that it is not the same as the existing file name, choose the optimal order of characters: #% — 0000123456789A ~ Z.

UNDELETE also has set up a file the function of protection measures, is beyond the scope of this course session, the reader is in use some features access to DOS manual.

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VII. other commands

(A) of the CLS — clear screen command

1 features: clear all the display on the screen, place the cursor in the upper left corner of the screen.

2 types: internal commands

3 formats: CLS

(2) the version command VER view system

1: display the current system version number

2 types: internal commands

VER 3 formats:

(3) DATA date settings command

1 function: set or display the system date.

2 types: internal commands

3 format: DATE [mm-dd-yy]

4 instructions for use:

(1) omitted [mm-dd-yy] show the system date and prompts for the new date, not modify directly press return, [mm-dd-yy] as "monthly — every day — every year" format;
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(2) when the machine starts, it is automatically processed file (AUTOEXEC.BAT) is executed, you are not prompted to enter the system date. Otherwise, the prompt for a new date and time.

(4) TIME system clock settings command

1 function: set or display the system time.

2 types: internal commands

3 format: TIME [hh: mm: ss: xx]

4 instructions for use:

(1) omitted [hh: mm: ss: xx] to display the system time and prompts for a new time, not modify directly press return, [hh: mm: ss: xx] "hours: minutes: seconds: fractions of a second" format;

(2) when the machine starts, it is automatically processed file (AUTOEXEC.BAT) is executed, the system does not prompt forThe system date. Otherwise, the prompt for a new date and time.