| 1 | #!/usr/bin/env bash |
| 2 | # Desc: Insert string into provided string |
| 3 | |
| 4 | yell() { echo "$0: $*" >&2; } |
| 5 | die() { yell "$*"; exit 111; } |
| 6 | must() { "$@" || die "cannot $*"; } |
| 7 | insertStr() { |
| 8 | # Desc: Inserts a string into another string at a specified position. |
| 9 | # Input: arg1: str str_rec String to receive insertion |
| 10 | # arg2: int pos Insertion position (0 = append to front) |
| 11 | # arg3: str str_ins String to be inserted |
| 12 | # Output: stdout: Combined string |
| 13 | # Version: 0.0.2 |
| 14 | # Depends: BK-2020-03: yell(), die(), must() |
| 15 | # Ref/Attrib: * BK-2020-03: https://gitlab.com/baltakatei/baltakatei-exdev/ |
| 16 | # * Cooper, Mendel. “Advanced Bash-Scripting Guide: Manipulating Strings”. tldp.org https://tldp.org/LDP/abs/html/string-manipulation.html |
| 17 | |
| 18 | local str_rec pos str_ins re len_str_rec; |
| 19 | local pfx_pos_start pfx_len pfx; |
| 20 | local sfx_pos_start sfx_len sfx; |
| 21 | |
| 22 | # Check args |
| 23 | if [[ $# -ne 3 ]]; then |
| 24 | yell "ERROR:Invalid argument count:$#"; |
| 25 | return 1; fi; |
| 26 | re='^[0-9]+$'; |
| 27 | if [[ ! "$2" =~ $re ]]; then |
| 28 | yell "ERROR:Not an int:$2"; |
| 29 | return 1; fi; |
| 30 | str_rec="$1"; |
| 31 | pos="$2"; |
| 32 | str_ins="$3"; |
| 33 | |
| 34 | # Calculate string stats |
| 35 | len_str_rec="${#str_rec}"; |
| 36 | |
| 37 | # Form prefix |
| 38 | pfx_pos_start="0"; |
| 39 | pfx_len="$pos"; |
| 40 | pfx="${str_rec:$pfx_pos_start:$pfx_len}"; |
| 41 | |
| 42 | # Form suffix |
| 43 | sfx_pos_start="$(( pos ))"; |
| 44 | sfx_len="$(( len_str_rec - pos ))"; |
| 45 | sfx="${str_rec:$sfx_pos_start:$sfx_len}"; |
| 46 | |
| 47 | # Print output to stdout |
| 48 | printf "%s%s%s\n" "$pfx" "$str_ins" "$sfx"; |
| 49 | }; # Insert string provided at indicated position via stdout |
| 50 | |
| 51 | |
| 52 | # Tests |
| 53 | printf "\"%s\" should read \"foobarbaz\"\n" "$(insertStr "foobaz" 3 "bar";)"; |
| 54 | |
| 55 | insertStr "foobaz" 0 "bar"; |
| 56 | insertStr "foobaz" 1 "bar"; |
| 57 | insertStr "foobaz" 2 "bar"; |
| 58 | insertStr "foobaz" 3 "bar"; |
| 59 | insertStr "foobaz" 4 "bar"; |
| 60 | insertStr "foobaz" 5 "bar"; |
| 61 | insertStr "foobaz" 6 "bar"; |
| 62 | insertStr "foobaz" 7 "bar"; |
| 63 | insertStr "foobaz" 999 "bar"; |