Below is the do loop script to check whether a variable exists in the .sas7bdat file or not and it's working fine.But is there any way to the check that if all the variable exist in file then assign some value.
rword = var1 var2 var3 var4
for rwords in $rword
do
cat $path | grep -i $rwords
if [ $? -gt 0 ];
then
echo "$rwords DOES NOT EXIST"
exit
else
echo "$rwords EXIST"
fi
done
Thank you
Since all the variable names are unique you can do something like this:
if [ "$(grep --count --extended-regexp --ignore-case 'var1|var2|var3|var4' "$path")" -eq 4 ]
then
[all variables exist]
fi
This, of course, is brittle in several ways:
It would count multiple occurrences of the same variable multiple times, so if you have var3 twice and no var4 it would succeed wrongly.
It would count occurrences of the variable name inside variable values, comments or other data structures in your file.
It would count substring matches such as var2foo.
A better solution would be to use a library which can parse the format reliably (such as sas7bdat). Bash is just bad at parsing any kind of complex file format.
Use grep -q:
check for any of the words
if grep -qE -- "$var1|$var2|$var3|var4" "$path"; then
check for all the words
if grep -q -- "$var1" "$path" && grep -q -- "$var2" "$path" && grep -q -- "$var3" "$path"; then
check for a single word
if ! grep -q -- "$var1" "$path"; then
Related
I have an .xcconfig file that I want to access via the terminal to access variables in the file. Is there a command or is there some way to do this? For example I have a variable called Build_Code = 1234. How would I access that?
Create a script to read the value of a variable.
Ex: .xconfig
var1 = value1
var2 = value2
get_value.bash
#!/bin/bash
#
# get_value.bash <file> <variable>
#
usage()
{
echo "Usage: get_value.bash <file> <variable>"
exit 1
}
#################################################
# Arguments
if [[ $# -eq 2 ]]
then
file="$1"
var="$2"
else
usage
fi
# Check if the file exists
if [[ ! -f "$file" ]]
then
echo "ERROR: file $file does not exist."
exit 2
fi
# Get the variable's value
grep -w "$var" "$file" | cut -d'=' -f2 | tr -d ' '
This simple version assumes the format of the lines is VARIABLE\s*=\s*VALUE.
The tr is to remove spaces around the value.
The VALUE cannot contain spaces.
The <file> argument could be hard coded if you will only ever check .xconfig
Many other solutions could be conceived, depending on the exact requirements, but this does the basic need you put in your question.
I have a script that is trying to find the presence of a given string inside a file of arbitrary text.
I've settled on something like:
#!/bin/bash
file="myfile.txt"
for j in `cat blacklist.txt`; do
echo Searching for $j...
unset match
match=`grep -i -m1 -o "$j" $file`
if [ $match ]; then
echo "Match: $match"
fi
done
Blacklist.txt contains lines of potential matches, like so:
matchthis
"match this too"
thisisasingleword
"This is multiple words"
myfile.txt could be something like:
I would matchthis if I could match things with grep. I really wish I could.
When I ask it to match this too, it fails to matchthis. It should match this too - right?
If I run this at a bash prompt, like so:
j="match this too"
grep -i -m1 -o "$j" myfile.txt
...I get "match this too".
However, when the batch file runs, despite the variables being set correctly (verified via echo lines), it never greps properly and returns nothing.
Where am I going wrong?
Wouldn't
grep -owF -f blacklist.txt myfile.txt
instead of writing an inefficient loop, do what you want?
Would you please try:
#!/bin/bash
file="myfile.txt"
while IFS= read -r j; do
j=${j#\"}; j=${j%\"} # remove surrounding double quotes
echo "Searching for $j..."
match=$(grep -i -m1 -o "$j" "$file")
if (( $? == 0 )); then # if match
echo "Match: $match" # then print it
fi
done < blacklist.txt
Output:
Searching for matchthis...
Match: matchthis
Searching for match this too...
Match: match this too
match this too
Searching for thisisasingleword...
Searching for This is multiple words...
I wound up abandoning grep entirely and using sed instead.
match=`sed -n "s/.*\($j\).*/\1/p" $file
Works well, and I was able to use unquoted multiple word phrases in the blacklist file.
With this:
if [ $match ]; then
you are passing random arguments to test. This is not how you properly check for variable net being empty. Use test -n:
if [ -n "$match" ]; then
You might also use grep's exit code instead:
if [ "$?" -eq 0 ]; then
for ... in X splits X at spaces by default, and you are expecting the script to match whole lines.
Define IFS properly:
IFS='
'
for j in `cat blacklist.txt`; do
blacklist.txt contains "match this too" with quotes, and it is read like this by for loop and matched literally.
j="match this too" does not cause j variable to contain quotes.
j='"match this too"' does, and then it will not match.
Since whole lines are read properly from the blacklist.txt file now, you can probably remove quotes from that file.
Script:
#!/bin/bash
file="myfile.txt"
IFS='
'
for j in `cat blacklist.txt`; do
echo Searching for $j...
unset match
match=`grep -i -m1 -o "$j" "$file"`
if [ -n "$match" ]; then
echo "Match: $match"
fi
done
Alternative to the for ... in ... loop (no IFS= needed):
while read; do
j="$REPLY"
...
done < 'blacklist.txt'
I am trying to add a condition in a for loop to check the existence of a file as well as check for file size > 0 KB.
Period file contains monthly data:
20180101
20180201
20180301
20180401
20180501
There are individual files created for each month. Suppose a file is not created for one month, (20180201), then the loop below should terminate.
For example:
xxx_20180101.txt
xxx_20180301.txt
xxx_20180401.txt
xxx_20180501.txt
if [[ $STATUS -eq 0 ]]; then
for per in `cat ${PATH}/${PERIOD}.txt | cut -f 1 -d";"`
do
for fl in `ls -1 ${PATH}/${FILE} | grep ${per}`
do
if [[ `ls -1 $fl | wc -l` -eq 0 ]]; then
echo "File not found"
STATUS=1
else
if [[ -s "$fl" ]]; then
echo "$fl contain data.">>/dev/null
else
echo "$fl File size is 0KB"
STATUS=1
fi
fi
done
done
fi
but ls -1 $fl | wc -l is not returning 0 value when the if condition is executed.
The following is a demonstration of what a best-practices rewrite might look like.
Note:
We do not (indeed, must not) use a variable named PATH to store a directory under which we look for data files; doing this overwrites the PATH environment variable used to find programs to execute.
ls is not used anywhere; it is a tool intended to generate output for human consumption, not machines.
Reading through input is accomplished with a while read loop; see BashFAQ #1 for more details. Note that the input source for the loop is established at the very end; see the redirection after the done.
Finding file sizes is done with stat -c here; for more options, portable to platforms where stat -c is not supported, see BashFAQ #87.
Because your filename format is well-formed (with an underscore before the substring from your input file, and a .txt after that substring), we're refining the glob to look only for names matching that restriction. This prevents a search for 001 to find xxx_0015.txt, xxx_5001.txt, etc. as well.
#!/usr/bin/env bash
# ^^^^ -- NOT /bin/sh; this lets us use bash-only syntax
path=/provided/by/your/code # replacing buggy use of PATH in original code
period=likewise # replacing use of PERIOD in original code
shopt -s nullglob # generate a zero-length list for unmatched globs
while IFS=';' read -r per _; do
# populate an array with a list of files with names containing $per
files=( "$path/$period/"*"_${per}.txt" )
# if there aren't any, log a message and proceed
if (( ${#files[#]} == 0 )); then
echo "No files with $per found in $path/$period" >&2
continue
fi
# if they *do* exist, loop over them.
for file in "${files[#]}"; do
if [[ -s "$file" ]]; then
echo "$file contains data" >&2
if (( $(stat -c +%s -- "$file") >= 1024 )); then
echo "$file contains 1kb of data or more" >&2
else
echo "$file is not empty, but is smaller than 1kb" >&2
fi
else
echo "$file is empty" >&2
fi
done
done < "$path/$period.txt"
Here's a refactoring of Mikhail's answer with the standard http://shellcheck.net/ warnings ironed out. I have not been able to understand the actual question well enough to guess whether this actually solves the OP's problem.
while IFS='' read -r per; do
if [ -e "xxx_$per.txt" ]; then
echo "xxx_$per.txt found" >&2
else
echo "xxx_$per.txt not found" >&2
fi
done <periods.txt
You are over engineering here. Just iterate over content of file with periods and search each period in a list of files. Like this:
for per in `cat periods.txt`
do
if ls | grep -q "$per"; then
echo "$per found";
else
echo "$per not found"
fi
done
I am learning bash. I would like to get the return value and matched line by grep at once.
if cat 'file' | grep 'match_word'; then
match_by_grep="$(cat 'file' | grep 'match_word')"
read a b <<< "${match_by_grep}"
fi
In the code above, I used grep twice. I cannot think of how to do it by grep once. I am not sure match_by_grep is always empty even when there is no matched words because cat may output error message.
match_by_grep="$(cat 'file' | grep 'match_word')"
if [[ -n ${match_by_grep} ]]; then
# match_by_grep may be an error message by cat.
# So following a and b may have wrong value.
read a b <<< "${match_by_grep}"
fi
Please tell me how to do it. Thank you very much.
You can avoid the double use of grep by storing the search output in a variable and seeing if it is not empty.
Your version of the script without double grep.
#!/bin/bash
grepOutput="$(grep 'match_word' file)"
if [ ! -z "$grepOutput" ]; then
read a b <<< "${grepOutput}"
fi
An optimization over the above script ( you can remove the temporary variable too)
#!/bin/bash
grepOutput="$(grep 'match_word' file)"
[[ ! -z "$grepOutput" ]] && (read a b <<< "${grepOutput}")
Using double-grep once for checking if-condition and once to parse the search result would be something like:-
#!/bin/bash
if grep -q 'match_word' file; then
grepOutput="$(grep 'match_word' file)"
read a b <<< "${grepOutput}"
fi
When assigning a variable with a string containing a command expansion, the return code is that of the (rightmost) command being expanded.
In other words, you can just use the assignment as the condition:
if grepOutput="$(cat 'file' | grep 'match_word')"
then
echo "There was a match"
read -r a b <<< "${grepOutput}"
(etc)
else
echo "No match"
fi
Is this what you want to achieve?
grep 'match_word' file ; echo $?
$? has a return value of the command run immediately before.
If you would like to keep track of the return value, it will be also useful to have PS1 set up with $?.
Ref: Bash Prompt with Last Exit Code
I am making a bash script where I want to find files that are equal to a variable. The equals will then be used.
I want to use "mogrify" to shrink a couple of image files that have the same name as the ones i gather from a list (similar to "dpkg -l"). It is not "dpkg -l" I am using but it is similar. My problem is that it prints all the files not just the equals. I am pretty sure this could be done with awk instead of a for-loop but I do not know how.
prog="`dpkg -l | awk '{print $1}'`"
for file in $dirone* $dirtwo*
do
if [ "basename ${file}" = "${prog}" ]; then
echo ${file} are equal
else
echo ${file} are not equal
fi
done
Could you please help me get this working?
First, I think there's a small typo. if [ "basename ${file}" =... should have backticks inside the double quotes, just like the prog=... line at the top does.
Second, if $prog is a multi-line string (like dpkg -l) you can't really compare a filename to the entire list. Instead you have to compare one item at a time to the filename.
Here's an example using dpkg and /usr/bin
#!/bin/bash
progs="`dpkg -l | awk '{print $2}'`"
for file in /usr/bin/*
do
base=`basename ${file}`
for prog in ${progs}
do
if [ "${base}" = "${prog}" ]; then
echo "${file}" matches "${prog}"
fi
done
done
The condition "$file = $prog" is a single string. You should try "$file" = "$prog" instead.
The following transcript shows the fix:
pax> ls -1 qq*
qq
qq.c
qq.cpp
pax> export xx=qq.cpp
pax> for file in qq* ; do
if [[ "${file} = ${xx}" ]] ; then
echo .....${file} equal
else
echo .....${file} not equal
fi
done
.....qq equal
.....qq.c equal
.....qq.cpp equal
pax> for file in qq* ; do
if [[ "${file}" = "${xx}" ]] ; then
echo .....${file} equal
else
echo .....${file} not equal
fi
done
.....qq not equal
.....qq.c not equal
.....qq.cpp equal
You can see in the last bit of output that only qq.cpp is shown as equal since it's the only one that matches ${xx}.
The reason you're getting true is because that's what non-empty strings will give you:
pax> if [[ "" ]] ; then
echo .....equal
fi
pax> if [[ "x" ]] ; then
echo .....equal
fi
.....equal
That's because that form is the string length checking variation. From the bash manpage under CONDITIONAL EXPRESSIONS:
string
-n string
True if the length of string is non-zero.
Update:
The new code in your question won't quite work as expected. You need:
if [[ "$(basename ${file})" = "${prog}" ]]; then
to actually execute basename and use its output as the first part of the equality check.
you can use case/esac
case "$file" in
"$prog" ) echo "same";;
esac