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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3
votes
2answers
51 views

Getting the current path in .desktop EXEC command

Im trying to make a .desktop file run a .sh which is stored in the same directory as the .desktop. The whole directory needs to be portable and moved from machine to machine. my run script is run.sh ...
2
votes
2answers
109 views

How to force watch to run under bash

The problem is that when watch is executed it runs sh and I get this error: sh: 1: func1: not found here is the code: #!/bin/bash func1(){ echo $1 } export -f func1 watch func1
3
votes
1answer
58 views

find files without extension

Let say I have: foo.txt bar baz.ooo If I use ls -1 !(*.*) then I'll get only bar on the output. Great, now I wish to have same results with find - some find -regex that will do the job. NOTE: ...
0
votes
0answers
21 views

How to return multiple select count in an array variable in shell

I have a 4 SQL count values which I want to return in an array record_count so that I can use that count values in some if statements later in the shell program. But I am not able to return the values ...
0
votes
0answers
14 views

command type “hashed”? [duplicate]

type displays information about a command's type. How would it be interpreted if used as a command name? What command "types" are there? In the following example, what does "hashed" mean? Is it ...
0
votes
1answer
39 views

What is “built-in” command in bash [duplicate]

cd is a built-in command in Bash. Is a built-in command or function in Bash the same concept as a built-in command or function in an interpreter language (e.g. Python)? Is "built-in" a concept of ...
1
vote
3answers
72 views

Problem when splitting command with backslash in unix prompt

I often use the space-backslash combination ( ) to split a command and its parameters into various lines and make it more readable: /home/user> ls -ltra \ > file1.txt \ > file2.txt ...
1
vote
1answer
17 views

svn: add all my new files and directories

I'm using Solaris 10. I need to add to SVN everything I've placed in the sub directories of my SVN checkout. I have added files and directories and sub directories - is there a command to take care of ...
7
votes
4answers
664 views

What is the source of help?

help displays information about builtin commands. What is the source of help? Does it maintain a database for builtin commands, or does it read some files of each builtin commands (similar to the ...
1
vote
1answer
22 views

How to slice a text file into several files of 100 lines each? [duplicate]

My question might be quite unclear here. I have a giant text file with values that looks like this 0.00601233 0.000139403 0.000133679 0.000139497 0.000141683 0.000141888 0.000138646 0.000133465 ...
3
votes
1answer
30 views

Why does the read command not take interactive options when run by sh?

I want to download a provisioning script that reads some configuration parameters via read, and execute it: curl http://example.com/provisioning.sh | sh The problem is, that the read command in the ...
1
vote
2answers
34 views

what's the right pattern to match my command

OS: AIX 7.1 I am working on a shell script which let user input some command and execute it, one of the commands is in this form: compile appname the appname only can be one of [ccms|asws], what's ...
0
votes
1answer
49 views

What is the difference between ~ and / in paths [duplicate]

When I first log in to Unix on my Mac, I usually see a ~ after my username in the command line. However, if I look at the apps contained in that directory ~/Applications they are not all of my ...
10
votes
3answers
591 views

Is there any major difference when comparing a variable as a string or as an int

Out of curiosity, when doing a bash variable comparison (its value being an integer) it's possible to test it against some predefined value either declared as an int or as a string. Sample script: ...
2
votes
1answer
26 views

setenv not working in tcsh

I am trying to install a program on my brand-new CentOs. The installation requires setenv, which apparently does not work, not even in the tcsh shell. Can anyone give me some advice? [Anna@anna ...
1
vote
1answer
52 views

How to run java service as a non-root user on CentOs 6

I have a script that starts a Java application as a service on CentOS 6: #!/bin/sh # chkconfig: - 80 20 SERVICE_NAME=cn4server PATH_TO_JAR=/usr/local/share/myserver/cn4server.jar ...
3
votes
1answer
21 views

annotate “include” file for grep with comments?

I do a grep sort that includes certain strings. That is, give me the lines in a file that DO contain certain strings. As in grep -fv include file > out That command looks in file and sends to ...
4
votes
1answer
39 views

How to update 'command cache' after change of soft links?

I have changed multiple soft links on my system with ln -f -s. When I view the link with ls -l, I see they point to the right target. However, when I try to run the command, it still tries to use the ...
6
votes
3answers
239 views

`/proc/$PID/cwd` : is there a POSIX equivalent?

Linux has a /proc directory and file‑system, which as far as I can tell, is not part of POSIX. In each /proc/$PID subdirectories, is a symbolic link, cwd, pointing to the actual working directory of ...
0
votes
0answers
23 views

Virtual serial port problem

Background: I've to test external GSM module, connected to PC with serial port. Since I'll have to either send messages both to do more, I need to create two virtual serial port (script provided by ...
4
votes
4answers
267 views

what does $* mean in shell [duplicate]

What does $* mean in shell? I have code two function, run_command and run_test, they are called like this: if [ -n "`echo ${GOAT_COMMANDS} | grep $1`" ]; then run_command $* else run_test $* fi ...
4
votes
1answer
50 views

Is it possible to put arithmetic expressions in a crontab?

I know I can do simple arithmetic in shell scripts, like so: #!/bin/bash ((sum = 1 + 2)) echo sum This will output 3 on execution. My question now is, can this kind of expressions be used in ...
2
votes
0answers
19 views

Running Custom commands in a Terminal Application [duplicate]

I'm running a terminal application in /dev/pts/X terminal that has its own console as:         What I need is to run commands specific to this application but from ...
8
votes
2answers
186 views

Redirecting output depending on grep regex

I am using gradle run to start a REST server. The output of the REST server looks like this: XXX.XXX.XX.XXX - <moreinfo> randomtext randomtext XXX.XXX.XX.XXX - <moreinfo> XXX.XXX.XX.XXX - ...
5
votes
1answer
163 views

Test -n gives unexpected result

I understand test -n <expression> to return false if the expression evaluates to a string length of greater than 0. Why then does the following happen? Macbook:~ echo ${#undeclared_variable} 0 ...
2
votes
2answers
38 views

how to filteri by asterisk or similar expression by rsync in zsh

I have a lot of files named like: /var/log/foo/2014-07-06-01.log ... /var/log/foo/2014-07-20-04.log Everyday I have several log files and I want to download specified day's log files: $ rsync ...
5
votes
2answers
148 views

How to zip a file and save it in another directory

How can I zip a file and save it in another directory using the command line? I have no space left in directory (100% full).
5
votes
2answers
217 views

Is it possible to use shell parameter variables ($1, …, $@) directly in CLI?

Sometimes it is necessary to emulate and verify the above variables in small examples and then can be copied immediately to some script, etc. I tried to solve by using a simple example in the ...
3
votes
4answers
65 views

Generate random numbers in specific range

After googling a bit I couldn't find a simple way to generate with a shell command a random number included in a specific range, between a minimum and a maximum. I read about /dev/random, ...
3
votes
1answer
47 views

Using inotify to monitor a directory but not working 100%

I have written a bash script to monitor a particular directory /root/secondfolder/: #!/bin/sh while inotifywait -mr -e close_write "/root/secondfolder/" do echo "close_write" done When I ...
2
votes
1answer
68 views

Accumulate Filename in a Log file using shell script

I have files with their names as ABC_-_123321.20140505_-_161500.CSV ABC_-_654145.20140506_-_135020.CSV String_-_SerialID.Date_-_Time.CSV StartDate, StartTime, EndDate and EndTime are given as ...
3
votes
1answer
48 views

redirect output for a command that takes in multiple arguments

this command is to redirect output of time to with multiple args: $ time wc test >wc.out 2>time.out unix programming environment book shows that the error output of time redirects to ...
1
vote
1answer
41 views

How to enclose a quoted variable in quotes

I want to call: ./mjpg_streamer -i "./input_uvc.so -r 320x240" -o "./output_http.so -w ./www" from a C program, running system(). The problem is that I have to enclose shell command in quotes, which ...
7
votes
3answers
680 views

Why do some commands not read from their standard input?

I wonder what when we should use pipeline and when we shouldn't. Say for instance, to kill certain process which handling pdf files, the following will not work by using pipeline: ps aux | grep pdf ...
1
vote
2answers
51 views

sh + how to use array in sh script in order to print all values in array

I want to use arrays in my sh script. My target is to create an array with the values a b c and print all values in the array. I succeeded to print each array, but I failed to print all values in ...
5
votes
3answers
134 views

Combining brace expansion and output redirection

Often, I use parameter expansion on the command-line, such as cp a.{ext1,ext2} which is expands to cp a.ext1 a.ext2 However, in many cases I do not use cp, but another tool, let's call it cat, ...
2
votes
1answer
43 views

Displays and their relative position in a shell script

I want to get information about the displays, something like xrandr, but with more info. I want to know their position. So if I have two or more displays connected I want to know how they are ...
2
votes
1answer
37 views

Extracting lines around keys from a file

I have a large file with around 15 million lines. The odd lines contains the keys (but not only the keys) and the even lines are the data. That is, the file is something like: WRTZ Tyrosine ...
7
votes
3answers
374 views

How to permanently change both STDOUT and STDERR color to grey?

This question is similar to Can I configure my shell to print STDERR and STDOUT in different colors? But I am looking for a solution that will allow me to change both STDOUT and STDERR to ONE color. ...
1
vote
1answer
49 views

How to find list of available shells by command-line?

How to list available shells for use by command-line?
2
votes
2answers
90 views

Change directory based on a pipeline's output

I want to go to a directory with using filter For example there is a file named this-is-awsome ls | grep this-is-awsome | xargs cd How can I go to a directory with filter?
3
votes
1answer
26 views

Is there an easy way to background a sudo shell?

A bit more details, what I'm looking for is some kind of ^Z for sudo shells. For instance when running a long command I can hit ^Z to suspend the command or when I do ~^Z in ssh after hitting Enter. ...
3
votes
3answers
105 views

Messed up bash.bashrc file, commands not working anymore

Trying installing Java, I tried to add it to the executable path with the line: export PATH=/usr/lib/jvm/jdk1.7.0_60/bin:$PATH in the system-wide /etc/bash.bashrc file. For some reason this ...
0
votes
1answer
76 views

long format of ps command in Solaris

Jobs with a long command-line is not printing in Solaris: bash-3.2$ /usr/ucb/ps auxwww | grep ftf | awk '{print $NF}' | head -5 /proj/cmp01/app/btws/cfg/btw /proj/cmp01/app/btws/cfg/btw ...
4
votes
1answer
90 views

How to make a variable from a subshell available in the parent shell

I've written a quick-and-dirty script to time some reports from a web service: BASE_URL='http://example.com/json/webservice/' FIRST=1 FINAL=10000 for report_code in $(seq 1 $FINAL); do (time -p ...
6
votes
1answer
66 views

Filetype and dereference when listing directory with LS command

I'm trying to combine arguments to the ls command to list a directory content. What I'm basically trying to achieve is listing the directory dereferencing all links, but showing explicitly that the ...
3
votes
1answer
45 views

`echo test?` prints `test2` but `ls test?` prints nothing

I was playing with bash globbing recently and I noticed the following: First, make 2 dirs: $ mkdir test $ mkdir test2 Then: $ echo test? Outputs (correctly): test2 But: $ ls test? Outputs ...
4
votes
2answers
124 views

What is the syntax for passing the output of a command to xargs?

As an example I am using xdotool to obtain the list of windows on my desktop, which outputs a list of numbers, one on each line. An example command for that is: xdotool search --name "a_program", ...
2
votes
1answer
132 views

What is the difference between filename=${1:-/etc/hosts} and filename=/etc/hosts? [duplicate]

What is the difference between filename=${1:-/etc/hosts} and filename=/etc/hosts? For example: filename=/etc/hosts if [ -r "$filename" ] && [ -s "$filename" ]; then md5sum $filename ...
1
vote
3answers
38 views

How do I set a file's mtime in epoch format?

I know how to get a file's mtime in epoch format: stat --format=%Y <file> But I have not been able to figure out how to set a file's mtime in epoch format. The touch(1) man page appears to ...