4
votes
4answers
150 views

Bash Scripting : Printing column data in the same row

I have written a bash script to calculate the size of a PostgreSQL database and print the output along with the date when the script was executed in a text file. The script code is as follows: ...
0
votes
1answer
41 views

How to display data in columns in two variables with the same format?

I coded the following to display data formatted in columns: str1='hello i am robert and your ma frnd' str2='thisisaverylongword thisistoohehehe andherefinishthe string hereis a other ...
3
votes
2answers
73 views

Command in variable one are affecting output of other variable when displayed together in UNIX

I am having two file naming Extra_info and Class_info Class_info contains data : stuId stuName stuClass S01 jagdeep First S02 harsh First S03 Roop Second S04 Kali Third ...
1
vote
3answers
55 views

return the numeric value of a indexed variable rather than its name [duplicate]

The following piece of code illustrates my problem I'm afraid I oversimplified it way too much in the first round. #!/bin/bash dogLover=1 catLover=2 for ii in dog cat do ...
1
vote
2answers
514 views

Print line numbers of files I am searching through [closed]

I am looking for a way to print the line number of files my script is going through. I have found $LINENO but when I do echo 'Found foo in file' $(basename $foo) 'on line' $LINENO >> foo.csv ...
4
votes
1answer
171 views

Ubuntu unattended install : echo keypress to dialog

Ubuntu 12.04 LTS Server 64 My unattended-mode bootstrap.sh script contains: apt-get upgrade -y I know that during execution a primitive UI for GRUB installation will be shown which requires ...
2
votes
1answer
68 views

'echo' eats part of the message

I want to write a script that will dump all partitions of my android device through the android debug bridge and since this is a time intensive process I want to notify the user about the progress by ...
0
votes
1answer
303 views

using bash script to output new script: need mixture of variables to be replaced and not replaced

I'm having a problem with bash variable substitution. Here's a silly example of what I am trying to do. I need to output a new script from a bash script. A line (see echo in my example) has a mixture ...
4
votes
2answers
257 views

Quoted vs unquoted string expansion

for i in $(xrandr); do echo "$i" ; done for i in "$(xrandr)"; do echo "$i"; done for i in "$(xrandr)"; do echo $i; done I understand why 1 differs from 2. But why does 3 give a different output ...
0
votes
4answers
272 views

echo a loop with variables command

I have several lists and want to run some commands over them. As lists are long I want to run those commands parallel to each other, hence using nohup. For every item I tried to echo a loop that ...
0
votes
2answers
92 views

Supress expansion of * in echo

I am working on a script which dynamically executes some queries on daily basis. These queries are coming from a table in the database. Here is the sample output of the query table: ...
0
votes
1answer
76 views

the use for echo without argument in shell scripting

I have a following bash script I encountered on the web that prints the power set of a given lines of elements. p() { [ $# -eq 0 ] && echo || (shift; p "$@") | while read r ; do echo ...
1
vote
1answer
1k views

How to put value of echo pipe netcat commands into variable [duplicate]

I have this command succession: echo -ne "/dev/shm/test.sh" | netcat 89.196.167.2 4567 and let's say it return a string like, for example "Hello...bla". (on the 89.196.167.2 i have made a server ...
3
votes
2answers
228 views

echo string >> file does not work

I wrote the following script: for filename in `find . -name '*'.cpp | grep $IN_REGEX | grep -v $OUT_REGEX` do echo "Output file is $OUTPUT_FILE" count=`git log --pretty=format: --name-only ...
2
votes
3answers
405 views

How to stop `grep` from truncating pipe output

Is there any way to have an echo at the end of a pipe simply append to the current output rather than removing it all? For example, how can I keep the output for my cat and grep and add "END OF ...
4
votes
2answers
271 views

Why am I observing different behaviour of echo?

I am a bash beginner and observed the below behavior of echo #!/bin/bash x=" hello" echo $x echo "$x" Now when I run the above code I get ronnie@ronnie:~$ bash test.sh hello hello ...
22
votes
1answer
870 views

Why does echo >file use more real time than echo | sed >file?

The example, below, surprised me. It seems to be counter intuitive... aside from the fact that there is a whisker more user time for the echo | sed combo. Why is echo using so much sys time when it ...
1
vote
2answers
3k views

How can I trim the carriage return from text that is being piped in bash?

I'm using this command to get my last typed command: history | cut -c 8- | tail -n 2 | head -n 1 It works very well in bash, removing the line numbers, but there is one problem I have with it, (er, ...
13
votes
4answers
7k views

How to delete line with echo?

I know that I could delete the last three chars with: echo -ne '\b\b\b' But how can I delete a full line? I mean I dont want to use: echo -ne ...
-1
votes
2answers
377 views

Copying a few lines from stdout to stderr - but only if stderr is different from stdout

I have a bash script "backup.sh", which prints out everything to stdout, including all the files that are transferred during backup. I'd like to make it possible to keep that full output, but when ...
3
votes
2answers
305 views

Weird output by echo

I was playing with echo $$ a while back. Well that displays that pid of the shell. But then I did echo ! which promptly displayed !. Then echo !! produced echo echo ! echo ! $echo !!! gave echo ...
21
votes
4answers
4k views

How to echo a bang!

I tried to create a script by echo'ing the contents into a file, instead of opening it with a editor echo -e "#!/bin/bash \n /usr/bin/command args" > .scripts/command The output: bash: ...