Parsing a command line parameter in script

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# 1  
Old 08-17-2011
Parsing a command line parameter in script

I have a simple script that builds a complex program call which passes a number of parameters to the program. I'm trying to enhance the script to include the value of the command line parameter in the name of a file being created. The problem I'm having is that the parameter may include a forward slash (/) which is not valid in filenames. Ideally I would like to replace any slashes with underscores. My script is called "sasi" and it will require a parameter which may contain 0 to n slashes. The first part of the parameter should be an 8-character string. If changing the slashes is too complicated, I'd be happy with capturing just the first 8 characters. I've been trying to use the 'cut' function to strip off the first 8, but it's not working. 'cut' may not be the best approach, but I think it will do the job if I get the syntax correct. However, I'm open to suggestions for better methods. The script begins like this:

# UNIX script to initiate interactive SAS session,
# log and lst files are saved as "session_mmddhhmn"
# in the lstsave and logsave directories
log_mo=`date | cut -c5-7`
log_da=`date | cut -c9,10`
log_dw=`date | cut -c1-3`
log_hr=`date | cut -c12,13`
log_mn=`date | cut -c15,16`
log_sc=`date | cut -c18,19`
log_zn=`date | cut -c21-23`
log_yr=`date | cut -c25-28`

eval 'parm=\${1} | cut -c1-8'
echo &parm

When I try to run it, I get the message "parm: not found". Any assistance would be most appreciated.
# 2  
Old 08-17-2011
could this be caused by the &parm in the last line? It should be $parm.

At the first glance, I don't believe what you are trying is going to work. But let's take 1 step at a time. Smilie Let me know once you have corrected the above issue.
# 3  
Old 08-17-2011
Well, the & was the cause of the error, apparently. However, changing that did not produce the desired result. What do you recommend as step 2?
# 4  
Old 08-17-2011
To have the string before the first slash:
mOut=$(echo ${1} | cut -d'/' -f1)

This User Gave Thanks to Shell_Life For This Post:
# 5  
Old 08-17-2011
@shell_life, thanks!! That was exactly what I had in mind.
# 6  
Old 08-17-2011
Save yourself a bunch of overhead by calling date once:

# save date output in a variable.

# Parse the elements into their own variables.
print $todaysdate|read dw mo da time zn yr

print $dw $mo $da $time $zn $yr

# If you really need the time elements split out:
print $time|read hr mn sc

print $hr $mn $sc

The read command will parse on the Input Field Seperator.

Last edited by gary_w; 08-17-2011 at 04:40 PM..
# 7  
Old 08-17-2011
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