Subst Command---folder directory mapped to local hard drive

Subst is an excellent command under DOS, for Windows98, its executable file subst. EXE under the C:\Windows\Command folder,
Windows XP and later versions should be in the C:\Windows\System32 folder, and its regular Chinese name should be "give the directory a drive letter command."
Its function is to replace the path name with the disk drive character so that the drive letter is equivalent to the specified subdirectory path.
Its command format is simple: Subst? Drive1?? Drive2?? Path? where "Drive1" is a virtual new drive letter that specifies the alternate disk path, "Drive2?" Path is the folder and its path that you want to override.
Users can use it to virtual any directory into a disk drive, if the user needs to remove the virtual letter, you can execute the substdrive1?/d command.
Also, not all programs can correctly use the drive letter generated by the subst command.
such as format, Sys, Fdisk, and some of the commands that are now commonly used, these commands must use the real drive,
They refuse to operate on a subst virtual drive. For network disk drives, the subst command is powerless.
Usage format
subst [disk] [path] replaces the disk character with the specified path, which will be used as a drive
Second, subst/d to remove the substitution [example] c:\dos>subst a:c:\temp? Replace a disk with a C disk temp directory
C:\>subst A:/d? Remove Replacement SUBST [drive1: [Drive2:]path]
SUBST drive1:/d drive1: Specifies the virtual drive to which you want to assign a path.

[Drive2:]path Specifies the physical drive and the path to be assigned to the virtual drive.
/d deletes the replaced (virtual) drive.
Type SUBST without any parameters to display the list of current virtual drives.

Advanced Usage Tips
A preliminary understanding of the use of the SUBST command and its use, may wish to look at some of its advanced skills: 1. Hide the drive. Subst is a virtual disk drive letter, although Microsoft recommends that users use the unused letter to virtual, but does not mean that it can not be virtual already exist in the letter, such as a disk, C disk. So the user can through the SUBST command virtual A, C and other letters, directly covering the existing letter, so that others can not see the real content of the disk, in order to hide the purpose of the real drive. For example, the user first creates a folder named "Aaa" under the D-Packing directory, preferably setting the folder's properties to read-only and hide. Then open "Autoexec" in the C-packing directory. BAT file, add the following code:

@echooff C:\Windows\System32\Subst A:D:\AAA

(Note: In Windows XP subst is in the System32 directory, other systems may be different)

In this way, the floppy disk icon becomes the hard disk every time the system starts, and the contents of it are changed so as to realize the purpose of cynical. When you need to restore, just run "Subst a:/d" at the MS-DOS (Command prompt) mode.

2. installation of special software. There are a few software in the installation will be prompted to extract the installation information from a disk, then only copy files to the floppy disk before installation. Without the need for this, the subst command can "trick" the software that needs to be installed with a floppy disk. 　　The user copies all the files in the floppy disk to any folder on the hard disk, then the folder can be installed successfully after using the SUBST command to virtual a disk. 3. The analog disc runs automatically. At present, most of the multimedia CD-ROM with an automatic command to facilitate the user's use. However, if you copy all the content on the disc to the hard drive, it will not work correctly. At this point, the user can be placed the contents of the CD folder virtual CD-ROM drive (Subst F:d:\guangpan, assuming that F is the CD-ROM), the software will work correctly.

Subst is a string-handling function in

Subst
Linux in Linux. The
subst
usage in makefile is $ (subst from,to,text), which changes the contents of the TEXT from from to
string processing functions in the Makefile
Format: $ (subst &L 　　t;from>;,<to>;,<text>;)
Name: string substitution function--subst.
Feature: Replaces <from>; strings in string <text>; with <to>;. 　
Return: The function returns the string that was replaced.
Example: $ (subst a,the,there is),
replaces "a" in "There is a" with "the", and returns "There is".