how can a executing bash script be paused?
in [Shell]
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From: Lao Ming on 18 Dec 2008 17:53 On Dec 17, 9:25 pm, Barry Margolin <bar...(a)alum.mit.edu> wrote: > In article > <b7812cb6-087e-48c0-8dda-e405433be...(a)q30g2000prq.googlegroups.com>, > Lao Ming <laoming...(a)gmail.com> wrote: > > > > > Is there something unusual about pausing a bash script? > > I admit that I haven't done any interactive input since I started > > using bash. I want to use 'read' from stdin in order to > > slow down a loop when doing: > > > bash -x script > > > I tried: > > > while [ condition ] ; do > > processing ... > > printf "%s" "Pause: " > > read mypause > > done > > > Thanks. > > but it doesn't work. > > It looks like it should work. Could you be more specific than "doesn't > work"? Well, this is the script that I am trying to debug. It's a small script and does only one thing. It collects the first character of each filename (excluding dot files) and places the char into an array (if it doesn't exist in the array already). The script does not produce output as it is right now. #! /bin/bash -f check_filename() { filename="${FILE##*/}" if [ "${filename:0:1}" = "." ] ; then FLAG="true" else if [ "$INDEX" != "$PREVIOUS_INDEX" ] ; then INDEX_ARRAY[$I]=$( echo "${filename:0:1}" |tr '[a-z]' '[A- Z]' ) (( I++ )) fi fi export INDEX_ARRAY } declare -a INDEX_ARRAY PREVIOUS_INDEX="" INDEX="0" I=0 find . -type f -name "[0-z]*" |sort -f | { while IFS= read -r FILE ; do FLAG="false" INCOMPLETE=$( echo "$FILE" |sed 's/^.\///' ) # remove ^"./" SLASH=$( echo "$INCOMPLETE" |grep '/' ) if [ "$SLASH" != "" ] ; then dirspec="${INCOMPLETE%/*}" #else # check_filename # [ "$FLAG" = "true" ] && continue #fi #if [ "$dirspec" != "" ] ; then dirname="${dirspec##*/}" if [ "$dirname" != "" ] ; then [ "${dirname:0:1}" = "." ] && continue else check_filename [ "$FLAG" = "true" ] && continue fi else check_filename # new [ "$FLAG" = "true" ] && continue # new #filename="${FILE##*/}" #[ "${filename:0:1}" = "." ] && continue fi PREVIOUS_INDEX="$INDEX" done echo "${INDEX_ARRAY[@]}" }
From: Barry Margolin on 19 Dec 2008 00:33 In article <b8348de8-cc78-4b6b-8ee8-4b7d3e9ae694(a)w39g2000prb.googlegroups.com>, Lao Ming <laomingliu(a)gmail.com> wrote: > On Dec 17, 9:25�pm, Barry Margolin <bar...(a)alum.mit.edu> wrote: > > In article > > <b7812cb6-087e-48c0-8dda-e405433be...(a)q30g2000prq.googlegroups.com>, > > �Lao Ming <laoming...(a)gmail.com> wrote: > > > > > > > > > Is there something unusual about pausing a bash script? > > > I admit that I haven't done any interactive input since I started > > > using bash. �I want to use 'read' from stdin in order to > > > slow down a loop when doing: > > > > > � �bash -x script > > > > > I tried: > > > > > while [ condition ] ; do > > > � � processing ... > > > � � printf "%s" "Pause: " > > > � � read mypause > > > done > > > > > Thanks. > > > but it doesn't work. > > > > It looks like it should work. �Could you be more specific than "doesn't > > work"? > > > Well, this is the script that I am trying to debug. It's a small > script > and does only one thing. It collects the first character of each > filename > (excluding dot files) and places the char into an array (if it doesn't > exist > in the array already). The script does not produce output as it is > right now. I don't see anything in your script that looks like the above piece that you said doesn't work. Do you want to put the pause inside the code that's receiving the piped output from find|sort? It will read from the pipe, not the terminal, so you'll need to redirect read's input from /dev/tty, as one of the other replies suggested. > > #! /bin/bash -f > > check_filename() > { > filename="${FILE##*/}" > if [ "${filename:0:1}" = "." ] ; then > FLAG="true" > else > if [ "$INDEX" != "$PREVIOUS_INDEX" ] ; then > INDEX_ARRAY[$I]=$( echo "${filename:0:1}" |tr '[a-z]' '[A- > Z]' ) > (( I++ )) > fi > fi > export INDEX_ARRAY > } > > > declare -a INDEX_ARRAY > PREVIOUS_INDEX="" > INDEX="0" > I=0 > find . -type f -name "[0-z]*" |sort -f | > { > while IFS= read -r FILE ; do > FLAG="false" > INCOMPLETE=$( echo "$FILE" |sed 's/^.\///' ) # remove ^"./" > SLASH=$( echo "$INCOMPLETE" |grep '/' ) > if [ "$SLASH" != "" ] ; then > dirspec="${INCOMPLETE%/*}" > #else > # check_filename > # [ "$FLAG" = "true" ] && continue > #fi > #if [ "$dirspec" != "" ] ; then > dirname="${dirspec##*/}" > if [ "$dirname" != "" ] ; then > [ "${dirname:0:1}" = "." ] && continue > else > check_filename > [ "$FLAG" = "true" ] && continue > fi > else > check_filename # new > [ "$FLAG" = "true" ] && continue # new > #filename="${FILE##*/}" > #[ "${filename:0:1}" = "." ] && continue > fi > PREVIOUS_INDEX="$INDEX" > done > echo "${INDEX_ARRAY[@]}" > } -- Barry Margolin, barmar(a)alum.mit.edu Arlington, MA *** PLEASE post questions in newsgroups, not directly to me *** *** PLEASE don't copy me on replies, I'll read them in the group ***
From: Lao Ming on 19 Dec 2008 11:31
On Dec 18, 9:33 pm, Barry Margolin <bar...(a)alum.mit.edu> wrote: > In article > <b8348de8-cc78-4b6b-8ee8-4b7d3e9ae...(a)w39g2000prb.googlegroups.com>, > Lao Ming <laoming...(a)gmail.com> wrote: > > > > > On Dec 17, 9:25 pm, Barry Margolin <bar...(a)alum.mit.edu> wrote: > > > In article > > > <b7812cb6-087e-48c0-8dda-e405433be...(a)q30g2000prq.googlegroups.com>, > > > Lao Ming <laoming...(a)gmail.com> wrote: > > > > > Is there something unusual about pausing a bash script? > > > > I admit that I haven't done any interactive input since I started > > > > using bash. I want to use 'read' from stdin in order to > > > > slow down a loop when doing: > > > > > bash -x script > > > > > I tried: > > > > > while [ condition ] ; do > > > > processing ... > > > > printf "%s" "Pause: " > > > > read mypause > > > > done > > > > > Thanks. > > > > but it doesn't work. > > > > It looks like it should work. Could you be more specific than "doesn't > > > work"? > > > Well, this is the script that I am trying to debug. It's a small > > script > > and does only one thing. It collects the first character of each > > filename > > (excluding dot files) and places the char into an array (if it doesn't > > exist > > in the array already). The script does not produce output as it is > > right now. > > I don't see anything in your script that looks like the above piece that > you said doesn't work. > > Do you want to put the pause inside the code that's receiving the piped > output from find|sort? It will read from the pipe, not the terminal, so > you'll need to redirect read's input from /dev/tty, as one of the other > replies suggested. Thanks, Barry. Now I understand why Chris suggested that. > > #! /bin/bash -f > > > check_filename() > > { > > filename="${FILE##*/}" > > if [ "${filename:0:1}" = "." ] ; then > > FLAG="true" > > else > > if [ "$INDEX" != "$PREVIOUS_INDEX" ] ; then > > INDEX_ARRAY[$I]=$( echo "${filename:0:1}" |tr '[a-z]' '[A- > > Z]' ) > > (( I++ )) > > fi > > fi > > export INDEX_ARRAY > > } > > > declare -a INDEX_ARRAY > > PREVIOUS_INDEX="" > > INDEX="0" > > I=0 > > find . -type f -name "[0-z]*" |sort -f | > > { > > while IFS= read -r FILE ; do > > FLAG="false" > > INCOMPLETE=$( echo "$FILE" |sed 's/^.\///' ) # remove ^"./" > > SLASH=$( echo "$INCOMPLETE" |grep '/' ) > > if [ "$SLASH" != "" ] ; then > > dirspec="${INCOMPLETE%/*}" > > #else > > # check_filename > > # [ "$FLAG" = "true" ] && continue > > #fi > > #if [ "$dirspec" != "" ] ; then > > dirname="${dirspec##*/}" > > if [ "$dirname" != "" ] ; then > > [ "${dirname:0:1}" = "." ] && continue > > else > > check_filename > > [ "$FLAG" = "true" ] && continue > > fi > > else > > check_filename # new > > [ "$FLAG" = "true" ] && continue # new > > #filename="${FILE##*/}" > > #[ "${filename:0:1}" = "." ] && continue > > fi > > PREVIOUS_INDEX="$INDEX" > > done > > echo "${INDEX_ARRAY[@]}" > > } > > -- > Barry Margolin, bar...(a)alum.mit.edu > Arlington, MA > *** PLEASE post questions in newsgroups, not directly to me *** > *** PLEASE don't copy me on replies, I'll read them in the group *** |