CODEWITHSUNDEEP
unixcommand
Petryanu
Petryanu

Reputation: 141

How to search patterns in a single line from a file in unix

Suppose I have file with a single line.

/a/n/v//9.3/b/ld  --verbose -o o/c/f/r1 -r o/c/f/fn.o o/c/f/fyt.o L/fs/ed/pl/tls/oe -L/apps/ose/5.5.3//lib/powerpc -lc -lrt -lm -lcp  -lel -lip -lubs -lpp -lpc /a/oe/5.3//g3/l/g.3/nf/libgcov.a  -lrds -l00_ex -lmcu /a/n/v//9.3/b/ld  --verbose -o o/ce/wef/r34

I want to search for the pattern starting with "-l" and arrange it in the below order in another file. 

-lc 
-lrt 
-lm 
-lcp  
-lel 
-lip 
-lubs 
-lpp 
-lpc 
-lrds 
-l00_ex 
-lmcu

What command could be used to search the pattern mentioned above?

Upvotes: 1

Views: 172

Answers (1)

shellter
shellter

Reputation: 37258

Here you go:

echo "/a/n/v//9.3/b/ld  --verbose -o o/c/f/r1 -r o/c/f/fn.o o/c/f/fyt.o L/fs/ed/pl/tls/oe -L/apps/ose/5.5.3//lib/powerpc -lc -lrt -lm -lcp  -lel -lip -lubs -lpp -lpc /a/oe/5.3//g3/l/g.3/nf/libgcov.a  -lrds -l00_ex -lmcu /a/n/v//9.3/b/ld  --verbose -o o/ce/wef/r34" \
| awk '{for (i=1;i<=NF;i++) {if ($i ~ /^-l/) print $i }}' | sort

output

-l00_ex
-lc
-lcp
-lel
-lip
-lm
-lmcu
-lpc
-lpp
-lrds
-lrt
-lubs

Needless to say, if you don't want the output sorted for some reason, just remove |sort on the end. It will then print the arguments in the order listed on the cmd-line. (I suppose sometimes that would be important).

I'm using a standard awk idom, of iterating per element over the provided input 

for (i=1;i<=NF;i++)

the i is a tmp variable, NF means N umber (of) F ields, meaning the num-of-fields in the current line. The test is done with regular expression test

if ($i ~ /^-l/ )

where $i is the value of the i'th position in the input, and ^ indicates "must be at the front of the string", while -l matches any of the inputs you have provided.

echoing your data to awk via a pipe shows that awk is very comfortable reading from std-in, so you can replace echo with grep yourSearchtarget yourFile | awk ... or any other command that will return the lines you need for processing.

IHTH

Upvotes: 1

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