C-从字符串中获取CLEAN数字变量

Question

I have been fiddling with some C programming for a little LCD project.

I have a string, which executed in BASH (script), gives back a value from 0 - 100 (Volume level) the string is like this :

!/bin/bash

amixer get 'DIYINHK Clock Selector',0 | awk '/[/ {getline; print $5}' | tr -d '[]%'

I need this value returning, so that i can use it in a if/else statement eg I think the value is returned in a ascii way or something ?

the printf output is right, eg. when amixer is 98, the printf onscreen is 98 but on lcd, there is a kind of _ after the 98.... like this : 98_ its a "returning" value of some kind ?

What i need, is a clean number which i can use as eg. :

if (get_volume <= 30)

statement;

else if (get_volume <=50 )

statement;

else if .... .......

here is a snippet :

FILE *fpipe;

char *command = (char *)"/home/pi/lcd/get_volume.sh"; // get_volume script

char line[256];

  if (! (fpipe = (FILE*)popen(command,"r")) ) { perror("PROBLEMS"); exit(1); } while ( fgets( line, sizeof line, fpipe)) 

lcdPosition(lcd, 0,0);

lcdPrintf(lcd, line); // Print output on LCD

printf("\\nline = %s \\n", line); // Print output on screen

Answer 1

atoi function converts a string representing a number to an int. So to get a "clean number", you need something like:

int volume = atoi(line);