Programming Forums > Script Programming > Bash / Shell Scripting

nuvox · May 25th, 2008, 7:39 AM

hey all

im trying to write a script, need some help

concept goes like this: i want to grep a file for a word/phrase, and depending on grep's output (basically, any output at all = found, NULL = not found) to do -something-.

basically, in pseudocode:

(Toggle Plain Text)

if(grep_output == NULL):
    echo "not found";
else:
    echo "found"

could someone point me in the right direction? thanks in advance!

nuvox · May 25th, 2008, 9:29 AM

okay, figured it out.

(Toggle Plain Text)

grep_output=`grep <word> <file>`
if [ "$grep_output" == "" ]; then
    echo "not found";
else
    echo "found";
fi

Jessehk · May 25th, 2008, 9:38 AM

 bash Syntax (Toggle Plain Text) 
#!/bin/bash
 
if grep "found" "example.sh" > /dev/null; then
    echo "Found"
else
    echo "Not found"
fi
#!/bin/bash

if grep "found" "example.sh" > /dev/null; then
    echo "Found"
else
    echo "Not found"
fi

May 25th, 2008, 7:39 AM	#1
nuvox Newbie Join Date: May 2008 Posts: 2 Rep Power: 0	if condition and grep hey all im trying to write a script, need some help concept goes like this: i want to grep a file for a word/phrase, and depending on grep's output (basically, any output at all = found, NULL = not found) to do -something-. basically, in pseudocode: (Toggle Plain Text) if(grep_output == NULL): echo "not found"; else: echo "found" if(grep_output == NULL): echo "not found"; else: echo "found" could someone point me in the right direction? thanks in advance!

May 25th, 2008, 9:29 AM	#2
nuvox Newbie Join Date: May 2008 Posts: 2 Rep Power: 0	Re: if condition and grep okay, figured it out. (Toggle Plain Text) grep_output=`grep <word> <file>` if [ "$grep_output" == "" ]; then echo "not found"; else echo "found"; fi grep_output=`grep <word> <file>` if [ "$grep_output" == "" ]; then echo "not found"; else echo "found"; fi

May 25th, 2008, 9:38 AM	#3
Jessehk The Oblivious One Join Date: May 2005 Location: Ontario, Canada Posts: 630 Rep Power: 4	Re: if condition and grep bash Syntax (Toggle Plain Text) #!/bin/bash if grep "found" "example.sh" > /dev/null; then echo "Found" else echo "Not found" fi #!/bin/bash if grep "found" "example.sh" > /dev/null; then echo "Found" else echo "Not found" fi __________________ Dr. Zoidberg: [ecstatic] I'm going to a movie... with FRIENDS!

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Programming Forums > Script Programming > Bash / Shell Scripting

if condition and grep