I'm glad we worked it out. Sometimes the obvious possibility just seems to unlikely to ask about.
The 2nd set of eyes is a valuable programming tool. :-) Thanks again for you help Don. Hopefully I won't pull too many more bonehead moves like that again. :-)
As a general rule: do not change directories inside a script at all (for exactly this reason, to avoid this confusion). Whenever you work on files make sure you always use absolute pathes like this:
The same goes for all other filenames. This way your script will work regardless of where you started it. If you work on several files using a variable for the directory part ensures they all land in the same place. The absolute worst you can do, though, is to use relative pathes:
If you ever find that in anyones code: have them promise never to write any shell script again. This is a surefire recipe for disaster because the script will (maybe) work if you call it from one directory and fail if you call it from another.
In general the script you call inherits the environment from its calling process - the command shell you used to call it. "Envrionent" means not only the values for variables (all that have been "export"ed before) like PATH, TZ (timezone), LANG, etc.. but also the current directory and similar things. It is good practice to make your script independent from this environment by setting it to a certain state except for the few variables where you explicitly want this effect to take place. This includes (but is not limited to) making it independent of the current path it was called from.
Hi,
when I try to redirect input and the command is described as a string within an array redirection does not work. why?
#!/bin/bash
dir=("tail < ./hello.txt")
tail < ./hello.txt #works
${dir} #does not work (2 Replies)
Hi,
#!/bin/bash
while ;
do
rm -f /tmp/pipe
mkfifo /tmp/pipe
./yuv4mpeg_to_v4l2 < /tmp/pipe &
mplayer tom_and_jerry.mp4 -vf scale=480:360 -vo yuv4mpeg:file=/tmp/pipe
sleep 65;
done
When I run this - after mplayer finishes playing video it says - Exiting... (End of... (2 Replies)
Hello all,
I have a for loop executing in a script that I want to redirect STDOUT to screen and to file, while directing STDERR to the bit bucket. Here is the general sentax of what I'm doing:
for i in thingy
do
some_command ${i}
done 1>&1 | tee ${LOGFILE} 2> /dev/null
What I am... (2 Replies)
All,
I have a requirement to write a script where I check for Input redirection when the script was executed, based on which I handle my logic. Below is the example:
my.script
#! /bin/ksh
# Not sure how to frame the if condition below
if ; then
echo "Input Redirected from a file"
... (7 Replies)
Hello members,
I get an unexpected "end of file" error while trying to execute the following piece of code in the bash / ksh shell. I'm assuming the problem is with using the "execute immediate statement"
#! /bin/bash
tname="table"
for i in *
do
sqlstr="create table $tname$i as select... (3 Replies)
Hello,
So I sorted my file as I was supposed to:
sort -n -r -k 2 -k 1 file1 | uniq > file2
and when I wrote
> cat file2
in the command line, I got what I was expecting, but in the script itself
...
sort -n -r -k 2 -k 1 averages | uniq > temp
cat file2
It wrote a whole... (21 Replies)
The behavior of the following 2 operations is unexpected. K1 and K2 are files here :-
1) cat < K1 K2
The above operation should actually display contents of the both files.
But it gives the contents of K2 only. How is that ?
2) cat > K1 K2
Above operation takes the contents of... (2 Replies)
I tried to cat a file to another user that was logged in, but I received an error message that displayed something like:
%cat funny > /dev/ttyp3
zsh: permission denied: /dev/ttyp3
Thank you all for your help (1 Reply)
01-24-2017
