Generate an iso file

In fact, it's easy to use the dd command. [Guo @ guo ~] $ Ddif/home/guo/me. shof/home/guo/win. sh records 0 + 1 read Records 0 + 1 write 159 bytes (159B) have been copied, 0.000139826 seconds, 1.1 MB/second above is/home/guo/me. s...

 

In fact, it's easy to use the dd command.

[Guo @ guo ~] $ Dd if =/home/guo/me. sh of =/home/guo/win. sh

Read records of 0 + 1

Records the write records of 0 + 1

159 bytes (159 B) copied, 0.000139826 seconds, 1.1 MB/second

 

The above is to generate the/home/guo/me. sh file into the win. iso file and save it in the/home/guo/folder.

 

Add the dd help document in redhat

 

[Guo @ guo ~] $ Dd -- help

Usage: dd [operand]...

Or: dd option

Copy the file, convert and format it according to the operand.

 

Bs = the number of bits read and write at a time (see ibs =, obs =)

Cbs = the number of bits converted at a time

Conv = CONVS convert a file according to the comma-separated flag list

Count = copy the specified number of blocks to the block

Ibs = number of bits read at a time (default: 512)

If = the file is read from the specified file

Iflag = the symbols are read as specified in the comma-separated symbol list

Obs = number of bits written to the specified bits at a time (default: 512)

Of = write the file to the specified file

Oflag = the symbol is written as specified in the comma-separated symbol list

Seek = skip the specified number of blocks at the beginning of the output

Skip = number of parts skipping the specified number of parts at the beginning of the input

Status = noxfer forbidden transmission statistics

 

A block or number of segments may contain one or more of the following suffixes:

C = 1, w = 2, B = 512, kB = 1000, K = 1024, MB = 1000*1000, M = 1024*1024, xM = M

GB = 1000*1000*1000, G = 1024*1024*1024, and so on for T, P, E, Z, Y.

 

Each CONV symbol may be:

 

Ascii is converted from EBCDIC to ASCII

Ebcdic is converted from ASCII code to EBCDIC code

IBM converted from ASCII code to replaced EBCDIC code

Block replaces the line breaks in the ending character block with long spaces.

Unblock replaces spaces at the end of a cbs block with a linefeed.

Lcase converts uppercase letters to lowercase letters

Notrunc does not intercept output files

Ucase converts lowercase characters to uppercase letters

Swab exchanges each pair of input data bytes

After noerror reads data, it continues.

Sync fills each input data block with NUL characters to the size of ibs.

Or unblock, it will be filled with spaces instead of NUL characters

After noerror reads data, it continues.

Sync fills each input block with NUL to the size of ibs

If it is used with block or unblock, it is filled with spaces instead of NUL.

Write the output file data to the disk before fdatasync ends.

Fsync is similar to above, but metadata is also written together

 

The FLAG symbol can be:

 

Append mode (only meaningful to the output; conv = notrunc is implied)

Direct use of direct I/O access mode

Directory fails unless it is a directory.

Dsync uses synchronous I/O access mode

Sync is similar to the above, but it also takes effect for metadata

Fullblock accumulates complete blocks for the input (iflag only)

Nonblock uses the non-blocking I/O access mode

Noatime does not update the access time

Noctty does not assign control terminals based on files

Nofollow does not follow the link file

 

Sending a USR1 signal to the running "dd" process causes

The I/O statistics are printed to the device with a standard error and the replication operation is resumed.

 

$ Dd if =/dev/zero of =/dev/null & pid = $!

$ Kill-USR1 $ pid; sleep 1; kill $ pid

18335302 + 0 records in

18335302 + 0 records out

9387674624 bytes (9.4 GB) copied, 34.6279 seconds, 271 MB/s

Author junjieguo