The shell is unix's command-line interface. You can type commands in a shell interactively, or write scripts to automate tasks. Use this tag for questions applying to /bin/sh and most compatible shells (ash, bash, ksh, zsh, …).

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Two errors when running ssh in a bash script [duplicate]

I try to run this script against a remote machine, to carry out login check, but have some problems executing it with no errors. I have the following error when I run the script: The Error: bash: -c: ...
3
votes
2answers
93 views

Select added lines from file

I have two versions of a file where the newer one has some lines added. The files are sorted (think of wordlists) and I want to print out the newly added lines (given file1 and file2). I know how to ...
-1
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1answer
35 views

Shell script to get all the directory starting with a certain letters

I need to write some shell script to get all the directory that start with certain letters and save the result list in a txt file eg. -all uppercase directory -all directory that starts with "Ab" ...
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0answers
23 views

printf>stdin unusable with read [duplicate]

With read, sending "a" to stdin is not equivalent to pressing "a" (or use your favorite letter/key). Tested this: ~$ read -n1 & fg [1] 11620 read Then "typed" "a" into the read process stdin ...
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1answer
40 views

unexpected end of file [closed]

Have written a small script for our Windows machine but getting the below mentioned error. syntax error: unexpected end of file.Can you please help me to resolve it. I have attached only part of my ...
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3answers
42 views

Running sh file only works if cd'd to scripts directory

I'm trying to run a .sh file, through the ./file.sh syntax. I, wrongly, thought it'd be possible to run: ./usr/bin/foo/bar.sh which just yields "No such file or directory". However, if I run: cd ...
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votes
3answers
114 views

Processing input line by line (with empty lines) from shell

In a shell script, I need to parse the output of a command line-by-line. The output may include empty lines, and these are relevant. I am using ash, not bash, so cannot resort to process substitution. ...
-1
votes
1answer
36 views

killall fails some time

Hi below is the script which is intended to kill all instances of the process "processName" but sometimes it is not able to kill the process and we see double instance of the same process how can I ...
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1answer
41 views

Make does not work when invoked from a bash script

So i just asked a question : for loop over a list This works perfectly now and outputs what i need. Now i want to link this to a makefile which should be called per variable in my list like this: ...
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2answers
39 views

Use a script for a telnet session

I have a problem with my script. It seems my password is wrong. #!/usr/bin/expect set ip [lindex $argv 0] spawn telnet $ip set timeout 10 expect "Login:" send "administrator\r" expect "Password:" ...
4
votes
3answers
181 views

Unpack file compressed in .txz and .tar with one command

I have a file compressed in *.txz. After unpacking it I received a *.tar file. Is there any way to unpack it twice with one command? I mean unpack file (*.tar).txz with one command? For know I'm do ...
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vote
3answers
218 views

Read longest line in file using while read loop?

I've been googling but I can't find any scripts that uses the while loop to read the lines. I'm stuck and I'm not sure on where to start Heres the question: Write a bash script longestline.sh that ...
3
votes
1answer
44 views

How do you get the first file in each subdirectory matching a list of file extensions?

How do you get the first file in each subdirectory matching a list of file extensions? My goal is to run a program on just any one of the files in a series of subdirectories. For example, below ...
2
votes
1answer
62 views

How to print last login time?

I'd like to know how to set in .bashrc file to print the last login time of users when logging into another user in terminal. I do know that with who or last, but I'd like something a little more ...
7
votes
2answers
397 views

Bash - how to run a command after the previous finished? [duplicate]

Currently I have a script.sh file with the following content: #!/bin/bash wget -q http://exemple.com/page1.php; wget -q http://exemple.com/page2.php; wget -q http://exemple.com/page3.php; I want to ...
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0answers
18 views

checkbox to automated sql scripts run

I want to provide a menu in a shell script that offers a check list of SQL scripts to run. I actually need to execute the selected SQL scripts but it's about 20 of them and that make it hard to cover ...
1
vote
1answer
18 views

Comparing variables in arithmetic

Was wondering if someone can take the time to explain the following: I have a directory of files (PDF), which I place into an array. shopt -s nullglob # Set array ...
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2answers
29 views

is the shell a frontend to the terminal? [duplicate]

Is the shell only an addon to the terminal, so that a terminal daemon has to work in order to to start a shell as its frontend. What controll does the terminal exherts upon the shell?
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1answer
27 views

what is the difference betwwen starting a command with nohup and &? [duplicate]

nohub and & seem to have a similar effect on the surface, they both start processes without occupying the shell from which they have been started, how do they differ on a deeper level?
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0answers
32 views

A way to distinguish between interleaved output from two background processes

If I have two backgrounded processes that produce input to STDOUT or STDERR (e.g., two installation scripts), is there an easy way to make these two output streams distinguishable? I guess I can pipe ...
3
votes
2answers
33 views

How can I catch a command exit code for later, in a Makefile?

I have a makefile, with a test suite target, like so: rcheck: foo This shows the output from the foo command on stdout, and returns an exit code from foo which is handled by make as normal. ...
2
votes
1answer
48 views

Supply the same filename as argument to two commands [duplicate]

On a git conflict, I can currently do: git diff path/to/some/file.txt ... after reviewing the diff, usually I want to do: git checkout --theirs path/to/some/file.txt && git add ...
6
votes
2answers
201 views

Issue in Standard Output and Error [duplicate]

If I type cat > file.txt 2>&1 then file.txt is created with the content of cat's standard input.  But if I do cat > file.txt 1>&2 then file.txt is created, but the file is ...
3
votes
2answers
98 views

On Ctrl+C, kill the current command but continue executing the script

I have a bash script, wherein I execute a line, sleep for sometime and then tail -f my log file to verify a certain pattern is seen, I press ctrl +c to get out of tail -f and then move to the next ...
2
votes
1answer
45 views

Debian Linux: Start/run application/process in another virtual terminal

You'll have to bare with my my Linux terminology is pretty bad. When I say virtual terminal I'm talking about when you press ctrl+alt+ a function key (F1-F12). I think they are called virtual ...
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2answers
9 views

Manually executing a CRON - Confused about params

I have this code snippet: $CUSER=tim $APPDIR=/var/www/testing $APPVENV=/var/www/testing/ven cat > $APPDIR/cronfile << EOF PWD=$APPDIR/$CUSER PATH=$APPVENV/bin:\$PATH 0 2 * * * testapp search ...
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votes
1answer
50 views

Command “>” failing in Embedded Linux only

I'm developing an app in Qt for Embedded Linux where I want to see how much (%) of the given partition is occupied. I found on the web that a way to do this would be by calling the df command passing ...
1
vote
3answers
145 views

The equivalent of cmd “for” in bash?

I'm a Linux newbie, and I only know little about bash (or any Linux shell - but I just use bash). I'm used to using for %c in (*.*) do {something} in cmd in Windows, and I really feel inconvenient ...
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2answers
44 views

How to use variables properly in this little script?

Here is a little script to retarget old-wrong symlinks that I want to make interactive. #!/bin/bash # retarget (broken) symbolink links interactively echo -n "Enter the source directory where ...
0
votes
2answers
41 views

How to add a column if line contains string?

If I have a tab-delimited file containing the following lines: Sample1-Baboon 1 2 3 4 Sample2-Human 1 2 3 4 Sample3-Human 1 2 3 4 Sample4-Baboon 1 2 3 4 How can I add a new column ...
2
votes
1answer
48 views

Equivalent of “which” in sh [duplicate]

I found out today while developing a shell script that which is not a builtin for sh. What is a good equivalent?
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1answer
41 views

Display result of a command right aligned in terminal

I have a script that goes through many different checks and I use the success, failure functions defined in /etc/init.d/functions to clearly show the action result on the terminal. That works great, ...
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0answers
31 views

Autocomplete issue in bash with equal sign (=)

I am trying to make autocomplete work and wroted a piece of code to demonstrate an issue I faced up: $ cat completion.sh function _completion_command() { compopt +o bashdefault +o default +o ...
52
votes
4answers
3k views

Why is `[` a shell builtin and `[[` a shell keyword?

As far as I know, [[ is an enhanced version of [, but I am confused when I see [[ as a keyword and [ being shown as a builtin. [root@server ~]# type [ [ is a shell builtin [root@server ~]# type [[ [[ ...
1
vote
4answers
47 views

Dynamically reference a file's name

In a single directory, I'd like to replace the first line of each file with the file's name. Each file has as the first line "TestRelation." I'd like to replace it with the file's name. I know I can ...
1
vote
3answers
86 views

How to pass an array to a function as an actual parameter rather than a global variable

Is there a way to pass an array to a function as one of its parameters? Currently I have #!/bin/bash highest_3 () { number_under_test=(${array[@]}) max_of_3=0 for ((i = 0; ...
1
vote
1answer
29 views

Can .bash_profile be auto sourced after change?

I'm always wondering if there's a way to do this. I don't want to type source after changing my .bash_profile all the time.
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votes
0answers
22 views

what is the meaning of “${x%*.*}” in shell? [duplicate]

While I am using the code as ${x%*.*} it is excluding the extension of the file. for e.g. $ x="file.txt" $ y="file.20150208.dat" $ echo "${x%\*.\*} ${y%\*.\*}" file file.20150208 But how this ...
0
votes
1answer
19 views

What is the meaning of “${name##*/}” in Shell [duplicate]

I have a code as while read name; do uuencode "$name" "${name##*/}"; done but I do not understand what is meaning of ##*/ in "${name##*/}" Google doesn't give good results. Can someone please ...
1
vote
2answers
135 views

Perform multiple commands on one line

There are two steps, that I would like to be run on one line: twinkle -c then call sip:in06khattab@sip.linphone.org Here is the output: I wanted to perform these two steps on one line, I ...
3
votes
3answers
134 views

How to rsync files between two remotes?

I would like to transfer files between two remote hosts using on local shell, but it seems rsync doesn't support synchronisation if two remotes are specified as follow: $ rsync -vuar host1:/var/www ...
0
votes
2answers
65 views

In a shell script, How to give a variable another value after one job is done?

I'm trying to make a script which will see if the directory exists and will zip all of its contents under it according to the name/path of the directory. The farthest I could go was - ...
0
votes
2answers
60 views

Help to read a flat file into unix and output to simplified csv like format for import into excel

I have a text file that has data written to it in the format below, its thousands of rows. The new record always begins with WHATEVER.RDNDISPLAY or WHATEVER.DSPLY_NAME. The name of the record is ...
4
votes
3answers
79 views

Bash, insert last used argument of current command

I'm aware that you can recall the last argument of the previous command with !$ and also cycle through previous arguments with ALT + . but can you recall the last argument used for the current command ...
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votes
5answers
60 views

sed to replace with backspace

I have trail.txt, which contains spice netlist. Now I want to replace all expanded parameters to one line only i.e. remove + and append that line to previous line. trail.txt data + net06706 ...
0
votes
4answers
32 views

adding programs to path [duplicate]

I have a load of tools that are kept in the /opt directory. The tools are organised like this: /opt/toolname/tool.sh. My question is, how can I add the tools in my /opt folder to my path, so i can run ...
3
votes
2answers
57 views

Loop over files returned from find?

I'm trying to piece together a script that recursively finds all the *.plist files in a directory and then operates on them. The script is below, but its producing unexpected results. The expected ...
0
votes
1answer
27 views

Running a “scheduled”/delayed script as sudo on server, via ssh - and right before ssh exit

This would have probably been answered by Keep running a script via ssh, if I didn't have to run a command as superuser. Let me try with an example: say on my server, I have this script as ...
1
vote
3answers
53 views

Shell script to find and count total number of characters in all the files

How can I make a script that finds every file in your home directory that is less than 3 days old and then gets a count of the total number of characters in all of these files?
0
votes
1answer
30 views

Error while executing a.out from C shell

I am in my home directory. And there is an executable a.out in there. I want to execute it like- /bin/csh ~/a.out ^F^E@@@@@▒^A▒^A^H^C^D^B^B@^B@^\^\^A^A^E@@: Event not found. Its not that I cannot ...