Overview
to do shell script Shell script Shell variable Shell Learning Topic SED
1: to do shell script
| back up my ebook |
| open set of application, like eclipse, a pdf, and set of excel and ppt at startup |
| connect net once aftet statup |
| install a set of basic software after OS installed ( eclipse, oracle, java, install some linux softare, etc ) |
2: Shell script
| Shell script | ||
| it is a file which declared a set of commands | ||
| Gawk | it is GNOME version of AWK | |
| AWK is utility used in shell script for string and text manipulation | ||
| As per my understanding AWK is like Expression language used in JSP, Spring configuration | ||
| AWK is best to manipulate feed files which is in a record-fields | ||
| it is pattern-matching language | ||
| Shell scipt | ||
| it is interpreted not compiled | ||
| it is readable as well as executable | ||
| script file passed as argument to a shell | ||
| if a file is executable (by chmod), it can be executed like other command | ||
| for a shell script we can create alias. But it is availble only current session | ||
| Other scripting language | ||
| perl | it is old style of scripting language | |
| python | object oriented scriptiong language | |
| tcl/tk | it is another scripting language. Used with x-window for GUI tool | |
| usage of shell script | ||
| Automation for common task | ||
| System administration |
3: Shell variable
| Shell variable declaration | |
| variable name are case-senstive like java | |
| variable is untyped | |
| decimal value is treated as text | |
| as best practice use CAPS for environment variable | |
| shell variable scope | |
| it is available for with in scope of session | |
| comment | |
| any line begin with # will be ignored | |
| white line | |
| any empty white line will be ignored |
4: Shell Learning Topic
| Building Blocks | variable, if, case, for, while, until, built-in commands, environment variable, command line arguments | |
| function | function, function file, function arguments | |
| pipe | pipe and filters | |
| File Handling | file permission and size check | |
| usage of “here file” | ||
| text processing | sed, awk, rc | GNU Sed, Ssed, BSD Sed, POSIX Sed, mod_sed and csed and etc. |
| usage of | fork() and exec() |
5: SED
| option | commond | description | |||
| sed | d | delete the current line in patten buffer | |||
| e | read the content from a file instead of pipe | ||||
| n/quiet/slient | dont printout the output of processing | ||||
| p | print the output. This 'p' always used along with 'n' flag | ||||
| location | tell the line no. | ||||
| address | it select as a range | ||||
| address negation | negate the selected range | ||||
| address step | |||||
| s | substituion | ||||