/alx-system_engineering-devops

Primary LanguageShell

DEVOPS

Shell commands

  • pwd: prints the current working directory
  • ls: list content of a directory
  • ls -l: Display current directory contents in a long format
  • ls -la: Display contents both with hidden files
  • ls -lna: Display contents both with hidden files with user and group IDs
  • ln -s - create a symbolic link
  • cp -un file - copy only file that does not exist
  • [[:upper:]] - uppercase
  • mkdir -p directory/directory1/directory2 - create a directory with trailing slash
  • flag -p - to show directories with a slash
  • flag -a - to display hidden files
  • flag -m - to display files with a comma
  • flag -v - to sort files

Creating a magic file

  • first, create the magic file
<offset> <datatype> <regex> <filename> data
# replace <offset> - number
# replace <datatype> - can be string, ling, double, etc.
# replace <regex> - expression to match
# replace <filename>
!:mime filename
# create a mime(Multipurpose Internet Mail Extensions)
  • Second, compile the file
file -C -m <filename.mgc>

Shell Permisssions

  • su user - Change user
  • groups - display the groups the current user is part of
  • chmod username file - change the owner of a file
  • g - represents user group
  • u - represents owner
  • o - represents others
  • a - represents all user
  • r - read permission (4 as the numerical val)
  • w - write permission (2 as the numerical val)
  • x - execute permission (1 as the numerical val)