Sponsored Content
Full Discussion: Bash Integers/String
Top Forums Shell Programming and Scripting Bash Integers/String Post 302876340 by wisecracker on Saturday 23rd of November 2013 06:07:37 AM
Old 11-23-2013
Hi Qazi...

You couldn't get it?
Code:
${parameter/pattern/string}

The pattern is expanded to produce a pattern just as in filename expansion. Parameter
is expanded and the longest match of pattern against its value is replaced with string.
If pattern begins with ‘/', all matches of pattern are replaced with string. Normally only
the first match is replaced. If pattern begins with ‘#', it must match at the beginning of
the expanded value of parameter. If pattern begins with ‘%', it must match at the end of
the expanded value of parameter. If string is null, matches of pattern are deleted and the
/ following pattern may be omitted. If parameter is ‘@' or ‘*', the substitution operation is
applied to each positional parameter in turn, and the expansion is the resultant list. If
parameter is an array variable subscripted with ‘@' or ‘*', the substitution operation is
applied to each member of the array in turn, and the expansion is the resultant list.

And BTW, just because you see characters representing a number does not mean it is an integer, (or float).
In the case of bash everything is a string and bash decides how to interpret strings according to how you code for them.
Example:-
Code:
Last login: Sat Nov 23 11:02:56 on ttys000
AMIGA:barrywalker~> echo -n 1234567890 > /tmp/string.txt
AMIGA:barrywalker~> hexdump -C < /tmp/string.txt
00000000  31 32 33 34 35 36 37 38  39 30                    |1234567890|
0000000a
AMIGA:barrywalker~> echo -n 1234567890.0987654321 > /tmp/string.txt
AMIGA:barrywalker~> hexdump -C < /tmp/string.txt
00000000  31 32 33 34 35 36 37 38  39 30 2e 30 39 38 37 36  |1234567890.09876|
00000010  35 34 33 32 31                                    |54321|
00000015
AMIGA:barrywalker~> _

 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

integers in the if statement

hi, im trying to compare two variables in csh to put in an if statement, eg: set a = $firstnum set b = $secondnum if ($a -ge $b) echo $a But I get an error ("if: Expression syntax"). How can I make csh see my variables as integers? thanks in advance! (5 Replies)
Discussion started by: Deanne
5 Replies

2. Programming

Using write() with integers in C

I'm trying to write an integer to a file using the write() function, but write() requires the parameter to be written to be a const void*. How would I go about doing this? also: using itoa() produces a " warning: implicit declaration of function 'itoa' " even though i have #included stdlib.h (2 Replies)
Discussion started by: h@run
2 Replies

3. Shell Programming and Scripting

bash problem when comparing integers

Hi, When I compare currentfiledate to reportfiledate I get a "-bash: currentfiledate=20090220080101 reportfiledate=20090219231245 if ; then echo -ne "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! \n" echo -ne "!! Running the load utility !! \n" fi Our... (15 Replies)
Discussion started by: rbournival
15 Replies

4. Shell Programming and Scripting

Add non-integers using ksh

I would like to add 4.7 and 1.2. However I am unable to do this with expr. Any simple ideas (even using something other than expr)? Example: me> expr 4 + 1 5 me> expr 4.7 + 1.2 expr: 0402-046 A specified operator requires numeric parameters. (18 Replies)
Discussion started by: 2dumb
18 Replies

5. Shell Programming and Scripting

Editing lists of integers in 1d files with bash shell

Hi, I need a script that will: 1. Go through about 20 different folders, each containing about 20 1d files. The 1d files go something like this: 22.253 37.707 78.117 112.374 127.944 156.067 180.956 233.785 249.256 ... (1 Reply)
Discussion started by: ac130pilot
1 Replies

6. Shell Programming and Scripting

Cancel down 2 integers

Wonderful evening to all of you! My problem has to possible starting points. Well, not really, but getting to either one is no problem at all. So i got either a string in the format of "1920x1080" or simply the integers X = 1920 and Y = 1080. When I am done, I would like to have an output... (5 Replies)
Discussion started by: jakunar
5 Replies

7. Shell Programming and Scripting

Grep float/integers but skip some integers

Hi, I am working in bash in Mac OSX, I have following 'input.txt' file: <INFO> HypoTestTool: >>> Done running HypoTestInverter on the workspace combined <INFO> HypoTestTool: The computed upper limit is: 11 +/- 1.02651 <INFO> HypoTestTool: expected limit (median) 11 <INFO> HypoTestTool: ... (13 Replies)
Discussion started by: Asif Siddique
13 Replies

8. UNIX for Dummies Questions & Answers

Strings to integers?

Hi, I'm totally new at this, so help will be appreciated. I have a directory with a bunch of files in it. The files are named xinteger_yinteger_zinteger.vtk (eg, x3_y0_z-1.vtk). I want to read the filenames and then assign the integers to variables that I then can use in expressions. So, for... (6 Replies)
Discussion started by: jhsinger
6 Replies

9. Shell Programming and Scripting

Comparing Integers (I think)

Hi, I can't figure out what I'm missing. I'm running a query to see if there are any streams recording on my DVR before starting a scripted update. I'm guessing that it is viewing $VIDEO as a string instead of an int. I've tried everything I saw on google but it still comes back as $VIDEO is... (8 Replies)
Discussion started by: Rhysers
8 Replies

10. UNIX for Beginners Questions & Answers

Escape bash-special character in a bash string

Hi, I am new in bash scripting. In my work, I provide support to several users and when I connect to their computers I use the same admin and password, so I am trying to create a script that will only ask me for the IP address and then connect to the computer without having me to type the user... (5 Replies)
Discussion started by: arcoa05
5 Replies
RBASH(1)						      General Commands Manual							  RBASH(1)

NAME
rbash - restricted bash, see bash(1) RESTRICTED SHELL
If bash is started with the name rbash, or the -r option is supplied at invocation, the shell becomes restricted. A restricted shell is used to set up an environment more controlled than the standard shell. It behaves identically to bash with the exception that the follow- ing are disallowed or not performed: o changing directories with cd o setting or unsetting the values of SHELL, PATH, ENV, or BASH_ENV o specifying command names containing / o specifying a file name containing a / as an argument to the . builtin command o specifying a filename containing a slash as an argument to the -p option to the hash builtin command o importing function definitions from the shell environment at startup o parsing the value of SHELLOPTS from the shell environment at startup o redirecting output using the >, >|, <>, >&, &>, and >> redirection operators o using the exec builtin command to replace the shell with another command o adding or deleting builtin commands with the -f and -d options to the enable builtin command o using the enable builtin command to enable disabled shell builtins o specifying the -p option to the command builtin command o turning off restricted mode with set +r or set +o restricted. These restrictions are enforced after any startup files are read. When a command that is found to be a shell script is executed, rbash turns off any restrictions in the shell spawned to execute the script. SEE ALSO
bash(1) GNU Bash-4.0 2004 Apr 20 RBASH(1)
All times are GMT -4. The time now is 10:00 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy