Imported from ../bash-2.0.tar.gz.

examples/scripts.noah/string.bash

@@ -0,0 +1,226 @@
+# string.bash --- bash emulation of string(3) library routines
+# Author: Noah Friedman <friedman@prep.ai.mit.edu>
+# Created: 1992-07-01
+# Last modified: 1993-09-29
+# Public domain
+
+# Conversion to bash v2 syntax done by Chet Ramey
+
+# Commentary:
+# Code:
+
+#:docstring strcat:
+# Usage: strcat s1 s2
+#
+# Strcat appends the value of variable s2 to variable s1. 
+#
+# Example:
+#    a="foo"
+#    b="bar"
+#    strcat a b
+#    echo $a
+#    => foobar
+#
+#:end docstring:
+
+###;;;autoload
+function strcat ()
+{
+    local s1_val s2_val
+
+    s1_val=${!1}			# indirect variable expansion
+    s2_val=${!2}
+    eval "$1"=\'"${s1_val}${s2_val}"\'
+}
+
+#:docstring strncat:
+# Usage: strncat s1 s2 $n
+# 
+# Line strcat, but strncat appends a maximum of n characters from the value
+# of variable s2.  It copies fewer if the value of variabl s2 is shorter
+# than n characters.  Echoes result on stdout.
+#
+# Example:
+#    a=foo
+#    b=barbaz
+#    strncat a b 3
+#    echo $a
+#    => foobar
+#
+#:end docstring:
+
+###;;;autoload
+function strncat ()
+{
+    local s1="$1"
+    local s2="$2"
+    local -i n="$3"
+    local s1_val s2_val
+
+    s1_val=${!s1}			# indirect variable expansion
+    s2_val=${!s2}
+
+    if [ ${#s2_val} -gt ${n} ]; then
+       s2_val=${s2_val:0:$n}		# substring extraction
+    fi
+
+    eval "$s1"=\'"${s1_val}${s2_val}"\'
+}
+
+#:docstring strcmp:
+# Usage: strcmp $s1 $s2
+#
+# Strcmp compares its arguments and returns an integer less than, equal to,
+# or greater than zero, depending on whether string s1 is lexicographically
+# less than, equal to, or greater than string s2.
+#:end docstring:
+
+###;;;autoload
+function strcmp ()
+{
+    [ "$1" = "$2" ] && return 0
+
+    [ "${1}" '<' "${2}" ] > /dev/null && return -1
+
+    return 1
+}
+
+#:docstring strncmp:
+# Usage: strncmp $s1 $s2 $n
+# 
+# Like strcmp, but makes the comparison by examining a maximum of n
+# characters (n less than or equal to zero yields equality).
+#:end docstring:
+
+###;;;autoload
+function strncmp ()
+{
+    if [ -z "${3}" -o "${3}" -le "0" ]; then
+       return 0
+    fi
+   
+    if [ ${3} -ge ${#1} -a ${3} -ge ${#2} ]; then
+       strcmp "$1" "$2"
+       return $?
+    else
+       s1=${1:0:$3}
+       s2=${2:0:$3}
+       strcmp $s1 $s2
+       return $?
+    fi
+}
+
+#:docstring strlen:
+# Usage: strlen s
+#
+# Strlen returns the number of characters in string literal s.
+#:end docstring:
+
+###;;;autoload
+function strlen ()
+{
+    eval echo "\${#${1}}"
+}
+
+#:docstring strspn:
+# Usage: strspn $s1 $s2
+# 
+# Strspn returns the length of the maximum initial segment of string s1,
+# which consists entirely of characters from string s2.
+#:end docstring:
+
+###;;;autoload
+function strspn ()
+{
+    # Unsetting IFS allows whitespace to be handled as normal chars. 
+    local IFS=
+    local result="${1%%[!${2}]*}"
+ 
+    echo ${#result}
+}
+
+#:docstring strcspn:
+# Usage: strcspn $s1 $s2
+#
+# Strcspn returns the length of the maximum initial segment of string s1,
+# which consists entirely of characters not from string s2.
+#:end docstring:
+
+###;;;autoload
+function strcspn ()
+{
+    # Unsetting IFS allows whitspace to be handled as normal chars. 
+    local IFS=
+    local result="${1%%[${2}]*}"
+ 
+    echo ${#result}
+}
+
+#:docstring strstr:
+# Usage: strstr s1 s2
+# 
+# Strstr echoes a substring starting at the first occurrence of string s2 in
+# string s1, or nothing if s2 does not occur in the string.  If s2 points to
+# a string of zero length, strstr echoes s1.
+#:end docstring:
+
+###;;;autoload
+function strstr ()
+{
+    # if s2 points to a string of zero length, strstr echoes s1
+    [ ${#2} -eq 0 ] && { echo "$1" ; return 0; }
+
+    # strstr echoes nothing if s2 does not occur in s1
+    case "$1" in
+    *$2*) ;;
+    *) return 1;;
+    esac
+
+    # use the pattern matching code to strip off the match and everything
+    # following it
+    first=${1/$2*/}
+
+    # then strip off the first unmatched portion of the string
+    echo "${1##$first}"
+}
+
+#:docstring strtok:
+# Usage: strtok s1 s2
+#
+# Strtok considers the string s1 to consist of a sequence of zero or more
+# text tokens separated by spans of one or more characters from the
+# separator string s2.  The first call (with a non-empty string s1
+# specified) echoes a string consisting of the first token on stdout. The
+# function keeps track of its position in the string s1 between separate
+# calls, so that subsequent calls made with the first argument an empty
+# string will work through the string immediately following that token.  In
+# this way subsequent calls will work through the string s1 until no tokens
+# remain.  The separator string s2 may be different from call to call.
+# When no token remains in s1, an empty value is echoed on stdout.
+#:end docstring:
+
+###;;;autoload
+function strtok ()
+{
+ :
+}
+
+#:docstring strtrunc:
+# Usage: strtrunc $n $s1 {$s2} {$...}
+#
+# Used by many functions like strncmp to truncate arguments for comparison.
+# Echoes the first n characters of each string s1 s2 ... on stdout. 
+#:end docstring:
+
+###;;;autoload
+function strtrunc ()
+{
+    n=$1 ; shift
+    for z; do
+	echo "${z:0:$n}"
+    done
+}
+
+provide string
+
+# string.bash ends here