Writing to file shell script - shell

I have been to trying to write some output to a CSV file using the method below in a shell script:
writeToResultFile()
{
resultFile="ShakeoutResult.csv"
msg=" $*"
echo "writing to resultFile..$msg"
echo $msg >> $resultFile
}
When I tried to call this method:
writeToResultFile "column1,column2,column3"
It works fine and was written to output file. But when I tried to call this method from another method such as:
doProcess()
{
writeToResultFile "data1,data2,data3"
}
Nothing is written to the output file. Stepping through, I know that writeToResultFile() is getting invoked and the param also is echoed in the console, but not getting appended to the output file.

Just to make sure: what do you use? Bash? Because it's working:
#!/bin/bash
writeToResultFile() {
msg=" $*"
echo "messaage: $msg"
echo $msg >> output.txt
}
doProcess()
{
writeToResultFile "function1,function2,function3"
}
writeToResultFile "main1,main2,main3"
doProcess
The output will be (cat output.txt):
main1,main2,main3
function1,function2,function3

Related

How to give a text file into a shell function?

Hi I'm trying to make a function which should get a text file and then do some things on it and then echo. But when I try to execute it, it says syntax error near unexpected token `"$cat"'
#!/bin/usr/bash
cat=$(< cat_dialogue.txt)
function test_cat (){
echo $1
}
test_cat($cat)
desired output:
>meow meow
Your program may look like the following. Note all differences. Check your scripts with shellcheck.
#!/usr/bin/env bash
cat=$(< cat_dialogue.txt)
test_cat() {
echo "$1"
}
test_cat "$cat"
Here is an example BASH function that strips a branchname:
#create function
function strip () {
#create local variable that takes input and fills $TEXT
local TEXT=$1
#stips the branch number from the branchname
echo $TEXT | sed 's/-[0-9]*//2'
}
strip "testbranch-12345-28796"
hope it helps :) also check the BASH documentation as mentioned by #joshmeranda

Random command not found error in shell script [duplicate]

Hi gusy I am trying to learn Bash and cannot seem to get this basic script to work.
#!/bin/bash
function system_info
{
echo "function system_info"
}
$(system_info)
I get a function: command not found issue.
Bash is trying to evaluate the string that is outputted by the system_info function. You'll want to try the following, which will just simply run the function:
system_info
or to store the outputted value to a variable:
value=$(system_info)
You need to invoke the function by saying:
system_info
$(...) is used for command substitution.
Invoke the function inside the script with just the function name and execute the script from the shell
#!/bin/bash
function system_info {
echo "function system_info"
}
system_info
#!/bin/bash
function system_info
{
echo "function system_info"
}
echo $(system_info)
Kind of redundant but it works without the command not found error.
Or This:
#!/bin/bash
function system_info
{
echo "function\n system_info"
}
printf "$(system_info)"
If you want to use newline character.
You can try this code in: https://www.tutorialspoint.com/execute_bash_online.php

Calling Shell-methods by chain of files in subdirectories

I'm trying to call methods from file to file with structure like:
/root
/subDir
/subSubDir
inSubSub.sh
inSub.sh
inRoot.sh
Files contents:
inRoot.sh:
#!/bin/bash
source ./subDir/inSub.sh
subMethod;
inSub.sh:
#!/bin/bash
source ./subSubDir/inSubSub.sh
subMethod () {
echo "I'm in sub"
}
subSubMethod;
inSubSub.sh:
#!/bin/bash
subSubMethod () {
echo "I'm in subSub"
}
subSubMethod;
Result of running $ ./inRoot.sh
subDir/inSub.sh: line 2: subSubDir/inSubSub.sh: No such file or directory
subDir/inSub.sh: line 6: subSubMethod: command not found
I'm in sub
So, it works for the first call but doesn't work deeper.
btw: using . ./ instead of source ./ returns the same
How to do it right, if it's possible?
You must change your inSub.sh like that
cat ./subDir/inSub.sh
#!/bin/bash
var="${BASH_SOURCE[0]}"
source "${var%/*}"/subSubDir/inSubSub.sh
subMethod () {
echo "I'm in sub"
}
subSubMethod;

Bash Function -> Command not found

Hi gusy I am trying to learn Bash and cannot seem to get this basic script to work.
#!/bin/bash
function system_info
{
echo "function system_info"
}
$(system_info)
I get a function: command not found issue.
Bash is trying to evaluate the string that is outputted by the system_info function. You'll want to try the following, which will just simply run the function:
system_info
or to store the outputted value to a variable:
value=$(system_info)
You need to invoke the function by saying:
system_info
$(...) is used for command substitution.
Invoke the function inside the script with just the function name and execute the script from the shell
#!/bin/bash
function system_info {
echo "function system_info"
}
system_info
#!/bin/bash
function system_info
{
echo "function system_info"
}
echo $(system_info)
Kind of redundant but it works without the command not found error.
Or This:
#!/bin/bash
function system_info
{
echo "function\n system_info"
}
printf "$(system_info)"
If you want to use newline character.
You can try this code in: https://www.tutorialspoint.com/execute_bash_online.php

Why do I get different bash script results when invoked with 'set -x', and how do I fix it?

I've found that the results of my bash script will change depending upon if I execute it with debugging or not (i.e. invoking set -x). I don't mean that I get more output, but that the result of the program itself differs.
I'm assuming this isn't the desired behavior, and I'm hoping that you can teach me how to correc this.
The bash script below is a contrived example, I tried reducing the logic from the script I'm investigating so that the problem can be easily reproducible and obvious.
#!/bin/bash
# Base function executes command (print working directory) stores the value in
# the destination and returns the status.
function get_cur_dir {
local dest=$1
local result
result=$((pwd) 2>&1)
status=$?
eval $dest="\"$result\""
return $status
}
# 2nd level function uses the base function to execute the command and store
# the result in the desired location. However if the base function fails it
# terminates the script. Yes, I know 'pwd' won't fail -- this is a contrived
# example to illustrate the types of problems I am seeing.
function get_cur_dir_nofail {
local dest=$1
local gcdnf_result
local status
get_cur_dir gcdnf_result
status=$?
if [ $status -ne 0 ]; then
echo "ERROR: Command failure"
exit 1
fi
eval dest="\"$gcdnf_result\""
}
# Cause blarg to be loaded with the current directory, use the results to
# create a flag_file name, and do logic with the flag_file name.
function main {
get_cur_dir blarg
echo "Current diregtory is:$blarg"
local flag_file=/tmp/$blarg.flag
echo -e ">>>>>>>> $flag_file"
if [ "/tmp//root.flag" = "$flag_file" ]; then
echo "Match"
else
echo "No Match"
fi
}
main
.
.
When I execute without the set -x it works as I expect as illustrated below:
Current diregtory is:/root
>>>>>>>> /tmp//root.flag
Match
.
.
However, when I add the debugging output with -x it doesn't work, as illustrated below:
root#psbu-jrr-lnx:# bash -x /tmp/example.sh
+ main
+ get_cur_dir blarg
+ local dest=blarg
+ local result
+ result='++ pwd
/root'
+ status=0
+ eval 'blarg="++ pwd
/root"'
++ blarg='++ pwd
/root'
+ return 0
+ echo 'Current diregtory is:++ pwd
/root'
Current diregtory is:++ pwd
/root
+ local 'flag_file=/tmp/++ pwd
/root.flag'
+ echo -e '>>>>>>>> /tmp/++ pwd
/root.flag'
>>>>>>>> /tmp/++ pwd
/root.flag
+ '[' /tmp//root.flag = '/tmp/++ pwd
/root.flag' ']'
+ echo 'No Match'
No Match
root#psbu-jrr-lnx:#
I think what happens is you capture the debugging logging output produced by the shell when you run it with set -x, this line, for example, does it:
result=$((pwd) 2>&1)
In the above line you shouldn't really need to redirect standard error to standard output, so remove 2>&1.
Changing...
result=$((pwd) 2>&1)
...into...
result=$(pwd 2>&1)
...will allow you to capture the output of pwd without capturing the debug info generated by set -x.
The reason the the $PWD variable exists is to free your script from having to run a separate process or interpret its output (which in this case has been modified by -x). Use $PWD instead.

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