# Test for Numeric
Sources: [stackoverflow 806906](https://stackoverflow.com/questions/806906/how-do-i-test-if-a-variable-is-a-number-in-bash) answer by F. Hauri "Some performance and compatibility hints"
```bash
isuint_Regx() { [[ $1 =~ ^[0-9]+$ ]] ;}
isint_Regx() { [[ $1 =~ ^[+-]?[0-9]+$ ]] ;}
isnum_Regx() { [[ $1 =~ ^[+-]?([0-9]+([.][0-9]*)?|\.[0-9]+)$ ]] ;}
```

Note that a more efficient way is using `case`, viz:
```bash
isuint_Case() { case $1 in ''|*[!0-9]*) return 1;;esac;}
isint_Case() { case ${1#[-+]} in ''|*[!0-9]*) return 1;;esac;}
isnum_Case() { case ${1#[-+]} in ''|.|*[!0-9.]*|*.*.*) return 1;; esac ;}
```