UNIX_shell_programming（几道练习题目）

Word Frequency

Given n files as command line arguments, calculate the frequency of words for each file, and display the results in a table. Words are defined to be one or more continuous list of letters (see the definition of letters above). Every non-letter character is to be considered whitespace.

The output should be a multi-column list, the first column being the list of words encountered (in lowercase) in any of the input files (sorted according to theC locale), and subsequent columns containing the number of occurrences of that word infile₁ ... file_n, separated by spaces. Example output for 2 files:

a 5 8the 6 3word 2 0she 3 5

#!/bin/bash# Word frequencies# $Id: unix9-wordfreq.sh 191 2006-03-29 11:07:00Z cactus $# See http://cactus.rulez.org/elte/2005-1-unix/#9 for a description of what it does# Licensed under the GNU General Public License, version 2function help () {    self=`basename $0`    cat << EOFUsage: $self FILE1 [FILE2...]Creates statistics about the words occuring in the files.Options:    -help   Display this help message(C) 2005 Dr. ERDI Gergo <[e-mail]>Version: \$Id: unix9-wordfreq.sh 191 2006-03-29 11:07:00Z cactus $EOF    exit 0}function error () {    echo ERROR: $@! >&2    exit 1}# Ez mashogy mukodik mint a tobbi: itt csak vegignezzuk az opciokat,# hogy van-e koztuk -helpfunction options () {    [ -z "$1" ] && return    case "$1" in-help)    help    ;;*)    [ -f "$1" -a -r "$1" ] || error "$1: Unable to open file"    shift    options "$@"    ;;    esac}function awk_count () {    AWKPROG='BEGIN {    FS="[^a-zA-ZáÁéÉíÍóÓöÖõÕúÚüÜûÛ]"        ekezet_lower["Á"] = "á";    ekezet_lower["É"] = "é";    ekezet_lower["Í"] = "í";    ekezet_lower["Ó"] = "ó";    ekezet_lower["Ö"] = "ö";    ekezet_lower["Õ"] = "õ";    ekezet_lower["Ú"] = "ú";    ekezet_lower["Ü"] = "ü";    ekezet_lower["Û"] = "û";}function iso88592_tolower (s) {    ret=""    for (j = 1; j <= length(s); j++)        ret = ret iso88592_tolower_c(substr(s, j, 1));    return ret;}function iso88592_tolower_c (c) {    if (match (c, "[a-zA-Z]"))        return tolower (c);    else if (c in ekezet_lower)        return ekezet_lower[c];    return c;}    /[a-zA-ZáÁéÉíÍóÓöÖõÕúÚüÜûÛ]/ {    for (i = 1; i != NF + 1; i++)    {        if (match ($i, "^[a-zA-ZáÁéÉíÍóÓöÖõÕúÚüÜûÛ]+$")){            words[iso88592_tolower($i)]++;}    }}END {        for (i in words)        printf "%s %s\n", i, words[i];}'    echo "awk '$AWKPROG' '$1' 2>/dev/null|sort"}# Ez elemenkenti feldolgozas, oriasi Fothi power :)function awk_join () {    AWKPROG='function read1 () {    if (!eof1) {        eof1 = (getline <= 0);        if (eof1)            return;                key1 = $1;        val1 = $2;        width = NF - 1;        for (i = 3; i <= NF; ++i)            val1 = sprintf ("%s %s", val1, $i);    }}function read2 () {    if (!eof2) {        eof2 = ((getline < f2) <= 0);        if (eof2)            return;                key2 = $1;        val2 = $2;    }}function join () {    printf "%s %s %s\n", key1, val1, val2;}function fill_from_1 () {    printf "%s %s 0\n", key1, val1, "0";}function fill_from_2 () {    printf "%s ", key2;    for (i = 0; i < width; ++i)        printf "0 ";    printf "%s\n", val2;}BEGIN {    FS=" ";    read1();    read2();        while (!eof1 || !eof2) {        if (key1 == key2) {            join();            read1();            read2();        } else if (eof2 || (!eof1 && (key1 < key2))) {            fill_from_1();            read1();        } else {            fill_from_2();            read2();        }    }    exit}'    echo "awk -v f2=<($1) '$AWKPROG' 2>/dev/null"}[ $# -lt 1 ] && error "Missing arguments"options "$@"fullpipe="$(awk_count $1)"shiftfor i in "$@"do  counter="`awk_count $i`"    awkline="`awk_join "$counter"`"    fullpipe="$fullpipe | $awkline"doneexport LANG=export LC_ALL=export LC_CTYPE=eval "$fullpipe"

转载自：http://gergo.erdi.hu/elte/2005-1-unix/