chapter 4 linux shells. table 4.1 shell locations and program names
TRANSCRIPT
Chapter 4
LINUX Shells
Table 4.1 Shell Locations and Program Names
Figure 4.1 Shell families and their relative functionalities
Table 4.2 Shell Similarities and Disimilarities
Table 4.2 Shell Similarities and Disimilarities (continued from previous slide)
Table 4.3 Some Useful Shell Built-In Commands
Table 4.4 Shell Environment Variables
Table 4.5 Shell Startup Files for Bash and TC Shells
Shell Startup Files
• Startup files set environment variables and set the initial behavior of the shell
• Bash first runs the file /etc/profile• Additional startup files have names that start
with “.” which denotes a hidden file
Figure 4.2 An illustration of the write command (continued on next slide)
Figure 4.2 An illustration of the write command (continued from previous slide
Table 4.6 Some Useful Aliases
Some Useful Commands
• Directory commands: pwd, mkdir, rmdir, ls• File display commands: cat, more, less• File printing: lpr• Calendar display: cal• Instant Messaging: write, talk (can be enabled or disabled
using mesg)• Email notification: enabled or disabled using biff• Aliasing: create an alias name for long commands (alias, and
unalias)• System statistics: uptime, ps
Shell Metacharacters
• Metacharacters are characters that have a special meaning to the shell
• Metacharacters can be used as regular characters by preceding them with “\”
Table 4.7 Shell Metacharacters (continued on next slide)
Table 4.7 Shell Metacharacters (continued from
previous slide)