Hello everybody,
I'm still slowly treading my way into bash scripting (without any prior programming experience) and hence my code is mostly what some might call "creative" if they meant well
I have created a script that serves its purpose but it does so very slowly, since it needs to work its way through ~1million lines of text file input and does so with a "while read line" loop, which slows down the process terribly.
It's not the read that's slow, it's "echo stuff | awk". You do that twice, so for a file with a million lines, you're running two million separate instances of awk! awk is a full-fledged language in its own right which you're loading, running, and quitting each time you use it. It's capable of processing more than one line, which is the efficient way to use it -- instead of 99% time spent loading/quitting, most time will be spent actually processing. You might as well do it all in awk.
You also have lots of useless use of backticks. Why do var=`echo stuff` when you can just do var=stuff ?
Incidentally, the shell can split variables by itself. You could do while read V1 V2 V3 V4 V5 V6 V7 to get rid of that first awk.
Hi Friends,
Can any of you explain me about the below line of code?
mn_code=`env|grep "..mn"|awk -F"=" '{print $2}'`
Im not able to understand, what exactly it is doing :confused:
Any help would be useful for me.
Lokesha (4 Replies)
Hi,
I need a command in UNIX KSH below is the description...
MAPPING DESCRIPTION ="Test Mapping for the calid inputs" ISVALID ="YES" NAME ="m_test_xml" OBJECTVERSION ="1" VERSIONNUMBER ="1"
unix ksh command to read the DESCRIPTION and write to a file
Test Mapping for the calid inputs... (3 Replies)
Hallo,
i need a Prompting read in my script:
read -p "Enter your command: " command
But i always get this Error:
-p: is not an identifier
When I run these in c-shell i get this error
/usr/bin/read: read: bad option(s)
How can I use a Prompt in the read command? (9 Replies)
Hello!
Sorry, for my not so perfect english!
I want to stop bash shell script execution until any key is pressed.
This line in a bash shell script
read -n1 -r -p "Press any key to continue..." key
produces this error
When I run this from the command line
usera@lynx:~$ read... (4 Replies)
Hi,
I have line in input file as below:
3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL
My expected output for line in the file must be :
"1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL"
Can someone... (7 Replies)
Hi All,
I'm completely new to bash scripting and still learning my way through albeit vey slowly.
I need to know where to insert my server names', my ip address numbers through out the script alas to no avail.
I'm also searching on how to save .sh (bash shell) script properly.... (25 Replies)
How to use "mailx" command to do e-mail reading the input file containing email address, where column 1 has name and column 2 containing “To” e-mail address
and column 3 contains “cc” e-mail address to include with same email.
Sample input file, email.txt
Below is an sample code where... (2 Replies)
Hi everybody,
I am new at Unix/Bourne shell scripting and with my youngest experiences, I will not become very old with it :o
My code:
#!/bin/sh
set -e
set -u
export IFS=
optl="Optl"
LOCSTORCLI="/opt/lsi/storcli/storcli"
($LOCSTORCLI /c0 /vall show | grep RAID | cut -d " "... (5 Replies)
Hello.
System : opensuse leap 42.3
I have a bash script that build a text file.
I would like the last command doing :
print_cmd -o page-left=43 -o page-right=22 -o page-top=28 -o page-bottom=43 -o font=LatinModernMono12:regular:9 some_file.txt
where :
print_cmd ::= some printing... (1 Reply)
Discussion started by: jcdole
1 Replies
LEARN ABOUT DEBIAN
rbash
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)