Shell Programming Learning: Shell Basics and files

1shell is an interface between the user and the kernel to interoperate,

2shell commands that can be run include Linux commands, built-in commands, utilities, user programs, shell scripts

3shell characters:

4. Get command help: Man,info.--help

5. The file type has a normal file (-), directory (d), Symbolic link files (l), character device files (c), block device files (b), sockets (s), Named Pipes (p), block device files are computer peripherals files that allow users to manipulate devices as well as normal files.

6, common file and directory operation commands:

LS, ls-al,ls-r recursively lists all subdirectories,-c,-t,-u sorted by the time of the file,

tree, display files and directory trees, tree-d does not display files, only show directories, L-N shows only a few levels of directories

PWD Displays the current directory

CD Switch Directory

mkdir Create a directory

RmDir Delete Empty Directory

Touch to generate an empty file or change the time stamp of the current file. -A change access time,-m change modification time,

CP copies files or directories,-d When copying symbolic link files corrections point to address,-F forced replication, I-Copy to confirm,-p preserves file attributes,-r,-r recursively copies all,

MV Mobile file or directory,-F forced replication,

RM deletes files or directories,-F sweeps nonexistent files,-r,-r recursively deletes all subdirectory files

LN, creating a linked file

symlinks, check the symbol link in the directory and display the type

7. File Packaging class command:

gzip,. gz file compression and decompression

-A, using ASCII text mode,-C compressed output, do not change the original file,-D decompression,-F forced Compression-l list compressed file information,-l display version and copyright,-N Compressed file, do not save file properties,-N Save file Properties-Q, do not display warnings,-r recursive processing,- T test compressed file,-V, display compression execution process, V-display version-< compression rate >,1 to 9, default is 6

bzip2,. bz2 file compression and decompression

-C compressed Output,-K retain the original file,-s to reduce usage,-D decompression,-F forced, T-Test, V-display process, V-display version,-< compression login >1~9, compressed block size--repetitive-best file has duplicate information, Can improve the compression effect,--repetitive-fast, if there are duplicate data appear, you can increase the compression speed,

Tar, file packing and unpacking,-F using f-f specified file name or device name,-v display process,-C Create package,-X Restore Backup,-t list the file name of the tar package,-Z with the GNU gzip compression,-Z with Compress compressed files or decompression,- J Use bzip2 compression or decompression