01-30-2017
Any system you will encounter nowadays will most likely contain a POSIX compliant shell. So I would code for that and I really do not see a need for backticks anymore.
There hardly is a reason nowadays why a new script would need to be able to run in a Bourne shell, which would require the backticks..
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1. Shell Programming and Scripting
Can someone explain the difference between backticks and system when
evaluated in these if statements:
sub getDate {
print "start date\n";
if ( system("/bin/date") ) {
print "can't get date\n";
exit(2);
}
print "finish date\n";
}
Returns the following:
start date
Thu... (5 Replies)
Discussion started by: gjkeenan
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2. Shell Programming and Scripting
Hi, I'm trying to do something like this: range= `expr `date '+%m'` - 1` and it does not work. How can I tell it to evaluate an expression within another expression evaluation? I was at first worried that `date '+%m'` would return a string but apparently expr does the math okay normally, so the... (3 Replies)
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3. UNIX for Dummies Questions & Answers
Hi,
I would like to change some lines in my mysql-dump, because there a syntax problems with some version of mysql.
I 'd like to change
USE ´someDatabase´;
to
USE someDatabase;
(without backticks) using the sed command in the shell
Thanks & best regards
Bernd (5 Replies)
Discussion started by: bjb
5 Replies
4. Shell Programming and Scripting
I'm always concerned I might be abusing backticks within my scripts. A current script I'm writing has this for example:
stripscriptname=`echo $scriptname | sed 's/\(.*\)\..*/\1/'`
stripsearch=`echo $searchpattern | tr -d ' ,/'`
Both of these variables are set inside the script (in fact,... (2 Replies)
Discussion started by: mglenney
2 Replies
5. Shell Programming and Scripting
Hey all. Just a fast question, what is the technical difference between using back ticks and using xargs to perform a command?
Here's an example
Find /mydir -name *.conf |xargs rm
Vs
Rm 'find /mydir -name *.conf'
Is there a performance hit? I know they do the same thing but which is... (1 Reply)
Discussion started by: msarro
1 Replies
6. Red Hat
Hi everyone. This is a bit of a perl/linux mixed question. I am trying to redirect STDOUT of chsh by using the following line of perl code.
system ("chsh -s /sbin/nologin $testing 1>/dev/null");
This should redirect STDOUT to /dev/null but it won't do that for some odd reason. Any ideas or... (6 Replies)
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7. Shell Programming and Scripting
Input file:
'data_1'
'data_10'
'data1311'
'235data_13'
Desired output:
data_1
data_10
data1311
235data_13
Can I know how to remove back tick"'" in a file?
Many thanks for advice. (3 Replies)
Discussion started by: perl_beginner
3 Replies
8. Shell Programming and Scripting
I have been testing a new script and cannot figure out why my `cat spath` will not execute on the remote machine?
sudo ssh -p 22344 -o "PasswordAuthentication no" -o "HostbasedAuthentication yes" -l testuser 192.168.1.6 "find `cat spath` -depth"
cat: spath: No such file or directory
but... (0 Replies)
Discussion started by: metallica1973
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9. Shell Programming and Scripting
I'm trying to make a dialog window that prints the output of grep that takes the output of find. Unfortunately my nested backticks don't work.
Here is the dialog window:
dialog --stdout --title "test" --backtitle "test" --msgbox "Test:\n `grep -l "${tablica}" `find $string``" 16 60I think I... (2 Replies)
Discussion started by: Starting_Leaf
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SCRIPT(1) BSD General Commands Manual SCRIPT(1)
NAME
script -- make typescript of terminal session
SYNOPSIS
script [-akq] [-t time] [file [command ...]]
DESCRIPTION
The script utility makes a typescript of everything printed on your terminal. It is useful for students who need a hardcopy record of an
interactive session as proof of an assignment, as the typescript file can be printed out later with lpr(1).
If the argument file is given, script saves all dialogue in file. If no file name is given, the typescript is saved in the file typescript.
If the argument command is given, script will run the specified command with an optional argument vector instead of an interactive shell.
The following options are available:
-a Append the output to file or typescript, retaining the prior contents.
-k Log keys sent to program as well as output.
-q Run in quiet mode, omit the start and stop status messages.
-t time
Specify time interval between flushing script output file. A value of 0 causes script to flush for every character I/O event. The
default interval is 30 seconds.
The script ends when the forked shell (or command) exits (a control-D to exit the Bourne shell (sh(1)), and exit, logout or control-D (if
ignoreeof is not set) for the C-shell, csh(1)).
Certain interactive commands, such as vi(1), create garbage in the typescript file. The script utility works best with commands that do not
manipulate the screen. The results are meant to emulate a hardcopy terminal, not an addressable one.
ENVIRONMENT
The following environment variable is utilized by script:
SHELL If the variable SHELL exists, the shell forked by script will be that shell. If SHELL is not set, the Bourne shell is assumed. (Most
shells set this variable automatically).
SEE ALSO
csh(1) (for the history mechanism).
HISTORY
The script command appeared in 3.0BSD.
BUGS
The script utility places everything in the log file, including linefeeds and backspaces. This is not what the naive user expects.
It is not possible to specify a command without also naming the script file because of argument parsing compatibility issues.
When running in -k mode, echo cancelling is far from ideal. The slave terminal mode is checked for ECHO mode to check when to avoid manual
echo logging. This does not work when in a raw mode where the program being run is doing manual echo.
BSD
January 22, 2004 BSD