Allow sh to be run from anywhere

Question

I have been monitoring the performance of my Linux server with ioping (had some performance degradation last year). For this purpose I created a simple script:

echo $(date) | tee -a ../sb-output.log | tee -a ../iotest.txt
./ioping -c 10 . 2>&1 | tee -a ../sb-output.log | grep "requests completed in\|ioping" | grep -v "ioping statistics" | sed "s/^/IOPing I\/O\: /" | tee -a ../iotest.txt
./ioping -RD . 2>&1 | tee -a ../sb-output.log | grep "requests completed in\|ioping" | grep -v "ioping statistics" | sed "s/^/IOPing seek rate\: /" | tee -a ../iotest.txt
etc

The script calls ioping in the folder /home/bench/ioping-0.6. Then it saves the output in readable form in /home/bench/iotest.txt. It also adds the date so I can compare points in time.

Unfortunately I am no experienced programmer and this version of the script only works if you first enter the right directory (/home/bench/ioping-0.6).

I would like to call this script from anywhere. For example by calling

sh /home/bench/ioping.sh

Googling this and reading about path variables was a bit over my head. I kept up ending up with different version of

line 3: ./ioping: No such file or directory

Any thoughts on how to upgrade my scripts so that it works anywhere?

Possible duplicate of [Getting the source directory of a Bash script from within](https://stackoverflow.com/questions/59895/getting-the-source-directory-of-a-bash-script-from-within) — dimo414, Sep 25 '17 at 00:48
Possible duplicate of [How do I run a program with a different working directory from current, from Linux shell?](https://stackoverflow.com/questions/786376/how-do-i-run-a-program-with-a-different-working-directory-from-current-from-lin) — tripleee, Sep 25 '17 at 04:50
`echo $(date)` is a [useless use of `echo`](http://www.iki.fi/era/unix/award.html#echo) and I get the feeling the rest of your script could also be simplified significantly. — tripleee, Sep 25 '17 at 08:03

John3136 · Answer 1 · 2017-09-25T01:04:52.457

0

Isn't it obvious? ioping is not in . so you can't use ./ioping.

Easiest solution is to set PATH to include the directory where ioping is. perhaps more robust - figure out the path to $0 and use that path as the location for ioping (assing your script sits next to ioping).

If iopinf itself depend on being ruin in a certain directory, you might have to make your script cd to the ioping directory before running.

edited Sep 25 '17 at 01:04

answered Sep 25 '17 at 00:38

John3136

28,809
4
51
69

Or rather, put `ioping` somewhere that already is in (or is commonly added to) one's path, such as `/usr/local/bin` or `~/bin`. – chepner Sep 25 '17 at 00:59

score 0 · Answer 2 · answered Sep 25 '17 at 00:40

The trick is the shell's $0 variable. This is set to the path of the script.

#!/bin/sh

set -x
cd $(dirname $0)
pwd

cd ${0%/*}
pwd

If dirname isn't available for some reason, like some limited busybox distributions, you can try using shell parameter expansion tricks like the second one in my example.

Allow sh to be run from anywhere

2 Answers2