Reading a value from a ini, compare and execute

AlMeu · 07-07-2020, 10:58 PM

Hi guys

I play in Pocky version with some scripts and I get problem with a very simple structure of "if" to compare a numeric value and execute something and I can't figure out why doesn't want execute correct.

The diag variable takes values 0 or 1.
I have a "system.ini" file where is memorized this numeric value:

Code:

[version]
diag=1

a library file "common.sh" where are defined common variables:

Code:

ModDIAG=$(awk -F "=" '/diag/ {print $2}' $dir/COMUN/Info/system.ini)

and in other script "test.sh" I try use this variable for enable some code for debug:

Code:

source $dir/scripts/common.sh

echo  "ModDiag=$ModDIAG" > /dev/kmsg
if [[ "$ModDIAG" -eq 1 ]]
then
	echo  "This is a test" > /dev/kmsg
fi
echo  "End test" > /dev/kmsg

at the end, no mater what condition I put in if, I get always on screen:

Code:

ModDiag=1
End test

The reading value is correct but if condition for numeric value doesn't execute.
What I miss?

Turbocapitalist · 07-07-2020, 11:52 PM

There probably shouldn't be quotes around a variable if it is to be treated like an integer.

You could try adding the following after the "source" line:

Code:

set -xv

That will show you what is actually in the variable and the exact line being parsed by the script.

However, there are perl and python modules for parsing INI files. If you're getting a more complex INI file to deal with, one of those might be worth looking at instead.

https://docs.python.org/3/library/configparser.html

https://metacpan.org/pod/Config::Any::INI

shruggy · 07-08-2020, 02:14 AM

Hmm,

Code:

$ bash -c '[[ "1" -eq 1 ]]&&echo yep||echo nay'
yep

OTOH, [[ ... ]] is not a POSIX-conform syntax, so if you have the #!/bin/sh shebang, and you /bin/sh is not Bash, then

Code:

$ dash -c '[[ 1 -eq 1 ]] 2>/dev/null&&echo yep||echo nay'
nay

AlMeu · 07-08-2020, 06:05 AM

It's a bash code #!/bin/bash
It's seams to be obvious the code but is just jumping over and never execute what is inside:

Code:

#!/bin/bash

echo "ModDiag=$ModDIAG"
if [[ "$ModDIAG" -gt 0 ]]; then
 echo "Test"
fi
echo "......"

I tried also:

Code:

echo "ModDiag=$ModDIAG"
bash -c '[[ "$ModDIAG" -eq 1 ]]&&echo "yes"||echo "no"'
echo "......"

and I get always:

Code:

ModDiag=1
......

It's not the problem the reading ini file. The value get in echo ModDiag is correct.
Only the comparation seams is not executing at all, just jumping.

NevemTeve · 07-09-2020, 03:54 AM

You might have some whitespace characters in your `system.ini` file (space, tab, carriage return etc)
Perhaps you should start it again from a working version (see the attached file).

dugan · 07-09-2020, 12:15 PM

Can you use Python?

Code:

>>> import configparser
>>> parser = configparser.ConfigParser()
>>> parser.read_string('''[version])
... diag=1''')
>>> parser['version']['diag']
'1'

Ser Olmy · 07-09-2020, 01:02 PM

Quote:

Originally Posted by AlMeu

The reading value is correct but if condition for numeric value doesn't execute.
What I miss?

That's a very good question, because I just replicated your setup by pasting the code/data into the three files involved (common.sh, system.ini, and the main batch file), and it seems to work just fine.

Please run the main file with "bash -x <filename>" and post the results.

dugan · 07-09-2020, 01:19 PM

If system.ini is literally the following:

Code:

[version]
diag=1

Code:

❯ tail -n 1 system.ini | cut -d = -f 2
1

dugan · 07-09-2020, 01:26 PM

I'm not getting your results?

Code:

❯ cat common.sh
ModDIAG=$(awk -F "=" '/diag/ {print $2}' system.ini)

❯ cat test.sh
#!/usr/bin/env bash

source common.sh

echo  "ModDiag=$ModDIAG"
if [[ "$ModDIAG" -eq 1 ]]
then
	echo  "This is a test"
fi
echo  "End test"

❯ bash test.sh
ModDiag=1
This is a test
End test

When I tried it, it's working as expected?

I tried adding some trailing whitespace to system.ini and it didn't change anything?

Skaperen · 07-11-2020, 07:58 PM

for things like this, i find the python language easier to achieve success. it is worth learning. all the major distributions of Linux include python version 3.

dugan · 07-14-2020, 10:04 AM

The first thing I did when I saw this thread was do a search for command-line ini parsers, and I was surprised when I didn't find one.

I mean, three of the options listed here are fairly standardized, and any of them could have been used to write one in C/C++.

https://stackoverflow.com/q/147902/240515

Anyone in the mood to do this?

shruggy · 07-14-2020, 11:08 AM

Quote:

Originally Posted by dugan

The first thing I did when I saw this thread was do a search for command-line ini parsers, and I was surprised when I didn't find one.

I did the same and found these two: crudini, confget.

SoftSprocket · 07-15-2020, 10:29 AM

Quote:

Originally Posted by dugan

The first thing I did when I saw this thread was do a search for command-line ini parsers, and I was surprised when I didn't find one.

I mean, three of the options listed here are fairly standardized, and any of them could have been used to write one in C/C++.

https://stackoverflow.com/q/147902/240515

Anyone in the mood to do this?

Why not - since there is no specification I guess you get to make up the rules. This version limits line length, reads a file or stdin, accepts a key or section:key as argument and prints its findings to stdout. Probably not very useful and I have no intention of doing anything farther with it but it did use up some, otherwise valuable, time. :P

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define LINE_BUFFER_SIZE 1025

void usage (char* app);
int get_section_key (char* arg, char** section, char** key);
int check_for_key (char* line, char* section);
int check_for_section (char* line);

int main (int argc, char** argv) {
	FILE* in;

	if (argc < 2) {
		usage (argv[0]);
		exit (EXIT_FAILURE);		
	}

	if (argc == 3) {
		in = fopen (argv[2], "r");
		if (in == NULL) {
			perror ("fopen");
			fprintf (stderr, "Unable to open %s for reading\n", argv[2]);
			usage (argv[0]);
			exit (EXIT_FAILURE);
		}
	} else {
		in = stdin;
	}

	char* section = NULL;
	char* key = NULL;

	int has_section = get_section_key (argv[1], &section, &key);

	int c = 0;
	char current_line[LINE_BUFFER_SIZE];
	char current_section[LINE_BUFFER_SIZE] = { 0 };
	
	int current_count = 0;
	int section_found = 0;

	while ((c = fgetc (in)) != EOF) {
		if (c == '\n') {
			if (current_count == 0) {
				continue;
			} 

			if (current_count == LINE_BUFFER_SIZE) {
				fprintf (stderr, "Maximum line length of %d exceeded\n", LINE_BUFFER_SIZE);
				exit (EXIT_FAILURE);	
			}

			current_line[current_count] = '\0';
			current_count = 0;			
			
			section_found = check_for_section (current_line);
			if (section_found) {
				strncpy (current_section, current_line + 1, strlen (current_line) - 2);
			} else {
				if (!has_section || (has_section && (strcmp (section, current_section) == 0))) {
					if (check_for_key (current_line, key)) {
						printf ("%s:%s\n", current_section, current_line);
					}
				} 

			}
		} else {
			current_line[current_count] = (char)c;
			++current_count;
		}
	}

	if (argc == 3) {
		fclose (in);
	} 

	if (!feof (in) && ferror (in)) {
		perror ("fgetc");
		exit (EXIT_FAILURE);
	}


	return EXIT_SUCCESS;
}


void usage (char* app) {
	printf ("usage: %s [section:]key [filename]\n", app);
}

int get_section_key (char* arg, char** section, char** key) {
	char* parg = arg;
	int has_section = 0;

	while (*parg != '\0') {
		if (*parg == ':') {
			has_section = 1;
			*parg = '\0';
			++parg;
			*key = parg;
			*section = arg;
			break;
		}
		
		++parg;	
	} 

	if (!has_section) {
		*key = arg;
	}

	return has_section;
}

int check_for_section (char* line) {
	int found = 0;
	int len = strlen (line);

	if (line[0] == '[' && line[len - 1] == ']') {
		found = 1;
	}

	return found;
}


int check_for_key (char* line, char* key) {
	char* pline = line;
	char* pkey = key;
	int found = 0;

	while (*pline != '\0') {
		if (*pline == '=') {
			found = 1;
			break;
		}
		
		if (*pkey == '\0') {
			break;
		}		
	
		if (*pline != *pkey) {
			break;
		}

		++pline;
		++pkey;
	}

	return found;
}

Code:

$ gcc -std=c11 -Wall ini_parser.c -o ini_parser
$ ./ini_parser
usage: ./ini_parser [section:]key [filename]
$ cat ./test.ini | ./ini_parser world
helo:world=true
names:world=earth
$ cat ./test.ini | ./ini_parser helo:world
helo:world=true
$ cat ./test.ini
[helo]
world=true
others=false
[names]
world=earth
moon=luna