Unix Shell Programming Third Edition phần 6 ppt
Unix Shell Programming Third Edition phần 6 ppt
... subsequently spawned subshells), the standard shell, /usr/bin/sh, is
started. From that point on, this new shell processes commands typed in from the terminal. When
Ctrl+d is typed to this shell, control ... executed from a subshell, the current directory of that subshell
HOME, James
Your home directory is where you're placed whenever you log on to the system. A special shell
var...
Unix Shell Programming Third Edition phần 4 pptx
... sticky area
that is a frequent source of shell programming errors. It's good to really understand the principles
here to save yourself a lot of programming headaches in the future.
There ... (that is, when $# already equals zero), you'll
get an error message from the shell (the error will vary from one shell to the next):
prog: shift: bad number
where prog is the name of t...
Unix Shell Programming Third Edition phần 5 pptx
... memo3
request id is laser1-35 (standard input)
$ run memo4
request id is laser1- 36 (standard input)
$
Incidentally, the shell permits filename substitution in the list of words in the for, meaning ... special notation is recognized by the shell when writing for commands. If you write
for var
do
command
command
done
(note the absence of the in), the shell automatically sequences th...
Unix Shell Programming Third Edition phần 9 ppt
... command-line option, or after set –o posix is executed.
Table 15.4. POSIX Shell, Korn Shell, and Bash Compatibility
POSIX Shell
Korn Shell
Bash
ENV file
X
X
POS
vi line edit mode
X
X
X
emacs line ... Variables
There are three different "types" of parameters: shell variables, special parameters, and positional
parameters.
Shell Variables
A shell variable name must...
Unix Shell Programming Third Edition phần 10 pptx
...
Bash shell
beginning of line, matching 2nd
bg command 2nd 3rd 4th 5th 6th
books
AWK Programming Language, The
Learning Pearl
Programming Pearl
Unix C Shell Field Guide, The
Unix in ... Shell Field Guide, The
Unix in a Nutshell[colon] System V Edition
Unix Programmer's Manual, Volume II
Unix Programming Environment, The
Bourne shell
Bourne, S...
Unix Shell Programming Third Edition phần 1 doc
...
Index
Unix Shell Programming, Third Edition
By Stephen G. Kochan, Patrick Wood
Publisher
: Sams Publishing
Pub Date
: February 27, 2003
ISBN
: 0 -67 2-32490-3
Pages
: 4 56
Slots
: 1
Unix Shell Programming ... shell, such as
bash. Three are covered in the third edition of Unix Shell Programming. It begins with a generalized
tutorial of Unix and tools and then mov...
Unix Shell Programming Third Edition phần 2 pot
... occurrences of " ;Unix& quot; in the text to " ;UNIX. " This can be easily
done in sed as follows:
$ sed 's /Unix/ UNIX/' intro Substitute Unix with UNIX
The UNIX operating system ... a particular string:
$ sed -n ' /UNIX/ p' intro Just print lines containing UNIX
The UNIX operating system was pioneered by Ken
the design of the UNIX system was to c...
Unix Shell Programming Third Edition phần 3 docx
... "What Is the Shell? ," you should realize that whenever you
type something like
who | wc -l
that you are actually programming in the shell! That's because the shell is interpreting ... use shell variables.
In the first case, the shell removes the extra whitespace characters from the line and passes echo
the four arguments one, two, three, and four (see Figure 6. 3)...
Unix Shell Programming Third Edition phần 7 pdf
... 2
and then execute a subshell, which in turn executes other shell programs as subshells. If an interrupt
signal is then generated, it will have no effect on the shells or subshells that are executing ... the subshells will be terminated.
Suppose that you execute the command
The IFS Variable
There is a special shell variable called IFS, which stands for Internal Field Separator. The she...
Unix Shell Programming Third Edition phần 8 doc
... what shell to start up when
you execute a shell escape. In such cases, you want to make sure that each time you start up a new
shell, you get the shell you want and not an older Bourne shell.
... you to interactive features of
the shell and two shells that have some nice features not found in the POSIX standard shell.
Getting the Right Shell
Most shells follow a convention...