| # basic cases |
| a=1 |
| a+=4 |
| echo $a |
| |
| x=(1 2 3) |
| x+=(4 5 6) |
| |
| echo ${x[@]} |
| |
| x[4]+=1 |
| echo ${x[@]} |
| |
| # trickier cases |
| # post-bash-4.2: bash understands += in environment assignments preceding |
| # command names |
| a+=5 printenv a |
| echo $a |
| |
| # if the integer flag is set, ksh93 appears to do arithmetic += and evaluate |
| # old value as an arithmetic expression |
| a= |
| typeset -i a |
| a+=7 |
| echo $a |
| |
| b=4+1 |
| typeset -i b |
| b+=37 |
| |
| echo $b |
| |
| unset x |
| x=(1 2 3 4 5) |
| |
| typeset -i x |
| |
| x[4]+=7 |
| |
| echo ${x[@]} |
| |
| unset x |
| typeset -i x |
| |
| x=([0]=7+11) |
| echo ${x[@]} |
| |
| unset x |
| x=(1 2 3 4 5) |
| |
| typeset -i x |
| |
| #x[4]=7+11 |
| |
| x=(1 2 3 4 [4]=7+11 ) |
| echo ${x[@]} |
| |
| x=( 1 2 [2]+=7 4 5 ) |
| echo ${x[@]} |
| |
| x+=( [3]+=9 [5]=9 ) |
| echo ${x[@]} |
| |
| unset a |
| a=1 |
| export a+=4 |
| printenv a |
| printenv a+ |
| |
| unset x |
| typeset -i x=4+5 |
| echo $x |
| |
| unset x |
| typeset x+=4 |
| echo $x |
| |
| typeset -i x+=5 |
| echo $x |
| |
| readonly x+=7 |
| echo $x |
| |
| x+=5 |
| |
| ${THIS_SH} ./appendop1.sub |
| ${THIS_SH} ./appendop2.sub |