diff options
Diffstat (limited to 'functions.sh')
| -rw-r--r-- | functions.sh | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/functions.sh b/functions.sh index 798c6c7..43a21e4 100644 --- a/functions.sh +++ b/functions.sh @@ -439,6 +439,47 @@ srandom() } # +# Takes the first parameter as a string (s), the second parameter as a numerical +# position (m) and, optionally, the third parameter as a numerical length (n). +# It shall then print a <newline> terminated substring of s that is at most, n +# characters in length and which begins at position m, numbering from 1. If n is +# omitted, or if n specifies more characters than are left in the string, the +# length of the substring shall be limited by the length of s. The function +# shall return 0 provided that none of the parameters are invalid. +# +substr() +{ + local i str + + if [ "$#" -lt 2 ]; then + warn "substr: too few arguments (got $#, expected at least 2)" + return 1 + elif ! is_int "$2"; then + _warn_for_args substr "$2" + return 1 + elif [ "$#" -ge 3 ]; then + if ! is_int "$3"; then + _warn_for_args substr "$3" + return 1 + elif [ "$3" -lt 0 ]; then + set -- "$1" "$2" 0 + fi + fi + str=$1 + i=0 + while [ "$(( i += 1 ))" -lt "$2" ]; do + str=${str#?} + done + i=0 + while [ "${#str}" -gt "${3-${#str}}" ]; do + str=${str%?} + done + if [ "${#str}" -gt 0 ]; then + printf '%s\n' "${str}" + fi +} + +# # Trims leading and trailing whitespace from one or more lines. If at least one # parameter is provided, each positional parameter shall be considered as a line # to be processed. Otherwise, the lines to be processed shall be read from the |