subcommand: Use pager for man output if possible.

[gsu.git] / subcommand

diff --git a/subcommand b/subcommand
index a9d388ba05232f49ac5f8adf37fd9f0df1a2ca45..ab6ae8a239b36609d6f6dbe1ce4b24e1e31087d1 100644 (file)
--- a/subcommand
+++ b/subcommand
@@ -50,6 +50,120 @@ _gsu_available_commands()
        } | sort | tr '\n' ' ')"
 }
 
        } | sort | tr '\n' ' ')"
 }
 

+# Check number of arguments.
+#
+# Usage: gsu_check_arg_count <num_given> <num1> [<num2>]
+#
+# Check that <num_given> is between <num1> and <num2> inclusively.
+# If only <num1> ist given, num2 is assumed to be infinity.
+#
+# Examples:
+#      0 0 no argument allowed
+#      1 1 exactly one argument required
+#      0 2 at most two arguments admissible
+#      2   at least two arguments required
+gsu_check_arg_count()
+{
+       ret=-$E_GSU_BAD_ARG_COUNT
+       if (($# == 2)); then # only num1 is given
+               result="at least $2 args required, $1 given"
+               (($1 < $2)) && return
+               ret=$GSU_SUCCESS
+               return
+       fi
+       # num1 and num2 given
+       result="need at least $2 args, $1 given"
+       (($1 < $2)) && return
+       result="need at most $3 args, $1 given"
+       (($1 > $3)) && return
+       ret=$GSU_SUCCESS
+}
+
+# Wrapper for the bash getopts builtin.
+#
+# Aborts on programming errors such as missing or invalid option string.  On
+# success $result contains shell code that can be eval'ed. For each defined
+# option x, the local variable o_x will be created when calling eval "$result".
+# o_x contains true/false for options without argument and either the empty
+# string or the given argument for options that take an argument.
+#
+# Example:
+#      gsu_getopts abc:x:y
+#      eval "$result"
+#      (($ret < 0)) && return
+#
+#      [[ "$o_a" = 'true' ]] && echo 'The -a flag was given'
+#      [[ -n "$o_c" ]] && echo "The -c option was given with arg $o_c"
+gsu_getopts()
+{
+       local i c tab=' ' cr='
+'
+
+       gsu_check_arg_count $# 1 1
+       if (($ret < 0)); then
+               gsu_err_msg
+               exit 1
+       fi
+
+       ret=-$E_GSU_GETOPTS
+       result="invalid optstring $1"
+       if [[ -z "$1" ]] || grep -q '::' <<< "$1" ; then
+               gsu_err_msg
+               exit 1
+       fi
+
+       for ((i=0; i < ${#1}; i++)); do
+               c=${1:$i:1}
+               case "$c" in
+               [a-zA-Z:]);;
+               *)
+                       ret=-$E_GSU_GETOPTS
+                       result="invalid character $c in optstring"
+                       gsu_err_msg
+                       exit 1
+               esac
+       done
+       result="local _gsu_getopts_opt"
+       for ((i=0; i < ${#1}; i++)); do
+               c1=${1:$i:1}
+               c2=${1:$(($i + 1)):1}
+               result+=" o_$c1="
+               if [[ "$c2" = ":" ]]; then
+                       let i++
+               else
+                       result+="false"
+               fi
+       done
+       result+="
+       OPTIND=1
+       while getopts $1 _gsu_getopts_opt \"\$@\"; do
+               case \"\$_gsu_getopts_opt\" in
+"
+       for ((i=0; i < ${#1}; i++)); do
+               c1=${1:$i:1}
+               c2=${1:$(($i + 1)):1}
+               result+="$tab$tab$c1) o_$c1="
+               if [[ "$c2" = ":" ]]; then
+                       result+="\"\$OPTARG\""
+                       let i++
+               else
+                       result+="true"
+               fi
+               result+=";;$cr"
+       done
+       result+="
+               *)
+                       ret=-\$E_GSU_GETOPTS
+                       result=\"invalid option given\"
+                       return
+                       ;;
+               esac
+       done
+       shift \$((\$OPTIND - 1))
+"
+       ret=$GSU_SUCCESS
+}
+

 _gsu_print_available_commands()
 {
        local cmd cmds
 _gsu_print_available_commands()
 {
        local cmd cmds


@@ -93,7 +207,9 @@ gsu_complete_options()
        done
 }
 
        done
 }
 

-export gsu_prefs_txt="
+com_prefs_options='e'
+
+_gsu_prefs_txt="

 Print the current preferences.
 
 Usage: prefs [-e]
 Print the current preferences.
 
 Usage: prefs [-e]


@@ -107,7 +223,7 @@ com_prefs()
 {
        local i conf="${gsu_config_file:=${HOME:-}/.$gsu_name.rc}"
 
 {
        local i conf="${gsu_config_file:=${HOME:-}/.$gsu_name.rc}"
 

-       gsu_getopts "e"
+       gsu_getopts "$com_prefs_options"

        eval "$result"
        (($ret < 0)) && return
        gsu_check_arg_count $# 0 0
        eval "$result"
        (($ret < 0)) && return
        gsu_check_arg_count $# 0 0


@@ -151,23 +267,35 @@ com_prefs()
        done
 }
 
        done
 }
 

+_gsu_isatty()
+{(
+       exec 3<&1
+       stty 0<&3 &> /dev/null
+)}
+

 complete_prefs()
 {
 complete_prefs()
 {

-       gsu_complete_options "e" "$@"
+       gsu_complete_options "$com_prefs_options" "$@"

 }
 
 }
 

-export gsu_man_txt="
+_gsu_man_txt='

 Print the manual.
 
 Print the manual.
 

-Usage: man"
+Usage: man

 
 

+If stdout associated with a terminal device, output is piped to
+$PAGER. If $PAGER is unset, less(1) is assumed.
+'

 
 com_man()
 {
        local equal_signs="=================================================="
        local minus_signs="--------------------------------------------------"
 
 com_man()
 {
        local equal_signs="=================================================="
        local minus_signs="--------------------------------------------------"

-       local com num
+       local com num pager='cat'

 
 

+       _gsu_isatty && pager="${PAGER:-less}"
+       [[ "$pager" == 'less' ]] && export LESS=${LESS-RI}
+       {

        echo "$gsu_name (_${gsu_banner_txt}_) manual"
        echo "${equal_signs:0:${#gsu_name} + ${#gsu_banner_txt} + 16}"
        echo
        echo "$gsu_name (_${gsu_banner_txt}_) manual"
        echo "${equal_signs:0:${#gsu_name} + ${#gsu_banner_txt} + 16}"
        echo


@@ -195,10 +323,11 @@ com_man()
                $0 help $com
                echo
        done
                $0 help $com
                echo
        done

+       } | $pager

        ret=$GSU_SUCCESS
 }
 
        ret=$GSU_SUCCESS
 }
 

-export gsu_help_txt="
+_gsu_help_txt="

 Print online help.
 
 Usage: help [command]
 Print online help.
 
 Usage: help [command]


@@ -206,7 +335,7 @@ Usage: help [command]
 Without arguments, print the list of available commands. Otherwise,
 print the help text for the given command."
 
 Without arguments, print the list of available commands. Otherwise,
 print the help text for the given command."
 

-export gsu_complete_txt="
+_gsu_complete_txt="

 Command line completion.
 
 Usage: complete [<cword> <word>...]
 Command line completion.
 
 Usage: complete [<cword> <word>...]


@@ -231,10 +360,10 @@ com_help()
                gsu_short_msg "### $gsu_name -- $gsu_banner_txt ###"
                _gsu_usage 2>&1
                {
                gsu_short_msg "### $gsu_name -- $gsu_banner_txt ###"
                _gsu_usage 2>&1
                {

-                       printf "com_help()\n$gsu_help_txt" | head -n 4; echo "--"
-                       printf "com_man()\n$gsu_man_txt" | head -n 4; echo "--"
-                       printf "com_prefs()\n$gsu_prefs_txt" | head -n 4; echo "--"
-                       printf "com_complete()\n$gsu_complete_txt" | head -n 4; echo "--"
+                       printf "com_help()\n$_gsu_help_txt" | head -n 4; echo "--"
+                       printf "com_man()\n$_gsu_man_txt" | head -n 4; echo "--"
+                       printf "com_prefs()\n$_gsu_prefs_txt" | head -n 4; echo "--"
+                       printf "com_complete()\n$_gsu_complete_txt" | head -n 4; echo "--"

                        grep -EA 2 "$ere" $0
                } | grep -v -- '--' \
                        | sed -En "/$ere/"'!d
                        grep -EA 2 "$ere" $0
                } | grep -v -- '--' \
                        | sed -En "/$ere/"'!d


@@ -263,22 +392,22 @@ com_help()
                return
        fi
        if test "$1" = "help"; then
                return
        fi
        if test "$1" = "help"; then

-               echo "$gsu_help_txt"
+               echo "$_gsu_help_txt"

                ret=$GSU_SUCCESS
                return
        fi
        if test "$1" = "man"; then
                ret=$GSU_SUCCESS
                return
        fi
        if test "$1" = "man"; then

-               echo "$gsu_man_txt"
+               echo "$_gsu_man_txt"

                ret=$GSU_SUCCESS
                return
        fi
        if test "$1" = "prefs"; then
                ret=$GSU_SUCCESS
                return
        fi
        if test "$1" = "prefs"; then

-               echo "$gsu_prefs_txt"
+               echo "$_gsu_prefs_txt"

                ret=$GSU_SUCCESS
                return
        fi
        if test "$1" = "complete"; then
                ret=$GSU_SUCCESS
                return
        fi
        if test "$1" = "complete"; then

-               echo "$gsu_complete_txt"
+               echo "$_gsu_complete_txt"

                ret=$GSU_SUCCESS
                return
        fi
                ret=$GSU_SUCCESS
                return
        fi


@@ -317,91 +446,6 @@ complete_help()
        echo "$result"
 }
 
        echo "$result"
 }
 

-# Wrapper for the bash getopts builtin.
-#
-# Aborts on programming errors such as missing or invalid option string.  On
-# success $result contains shell code that can be eval'ed. For each defined
-# option x, the local variable o_x will be created when calling eval "$result".
-# o_x contains true/false for options without argument and either the empty
-# string or the given argument for options that take an argument.
-#
-# Example:
-#      gsu_getopts abc:x:y
-#      eval "$result"
-#      (($ret < 0)) && return
-#
-#      [[ "$o_a" = 'true' ]] && echo 'The -a flag was given'
-#      [[ -n "$o_c" ]] && echo "The -c option was given with arg $o_c"
-gsu_getopts()
-{
-       local i c tab=' ' cr='
-'
-
-       gsu_check_arg_count $# 1 1
-       if (($ret < 0)); then
-               gsu_err_msg
-               exit 1
-       fi
-
-       ret=-$E_GSU_GETOPTS
-       result="invalid optstring $1"
-       if [[ -z "$1" ]] || grep -q '::' <<< "$1" ; then
-               gsu_err_msg
-               exit 1
-       fi
-
-       for ((i=0; i < ${#1}; i++)); do
-               c=${1:$i:1}
-               case "$c" in
-               [a-zA-Z:]);;
-               *)
-                       ret=-$E_GSU_GETOPTS
-                       result="invalid character $c in optstring"
-                       gsu_err_msg
-                       exit 1
-               esac
-       done
-       result="local _gsu_getopts_opt"
-       for ((i=0; i < ${#1}; i++)); do
-               c1=${1:$i:1}
-               c2=${1:$(($i + 1)):1}
-               result+=" o_$c1="
-               if [[ "$c2" = ":" ]]; then
-                       let i++
-               else
-                       result+="false"
-               fi
-       done
-       result+="
-       OPTIND=1
-       while getopts $1 _gsu_getopts_opt \"\$@\"; do
-               case \"\$_gsu_getopts_opt\" in
-"
-       for ((i=0; i < ${#1}; i++)); do
-               c1=${1:$i:1}
-               c2=${1:$(($i + 1)):1}
-               result+="$tab$tab$c1) o_$c1="
-               if [[ "$c2" = ":" ]]; then
-                       result+="\"\$OPTARG\""
-                       let i++
-               else
-                       result+="true"
-               fi
-               result+=";;$cr"
-       done
-       result+="
-               *)
-                       ret=-\$E_GSU_GETOPTS
-                       result=\"invalid option given\"
-                       return
-                       ;;
-               esac
-       done
-       shift \$((\$OPTIND - 1))
-"
-       ret=$GSU_SUCCESS
-}
-

 com_complete()
 {
        local cmd n cword
 com_complete()
 {
        local cmd n cword


@@ -554,32 +598,3 @@ gsu()
        _gsu_print_available_commands
        exit 1
 }
        _gsu_print_available_commands
        exit 1
 }

-
-# Check number of arguments.
-#
-# Usage: gsu_check_arg_count <num_given> <num1> [<num2>]
-#
-# Check that <num_given> is between <num1> and <num2> inclusively.
-# If only <num1> ist given, num2 is assumed to be infinity.
-#
-# Examples:
-#      0 0 no argument allowed
-#      1 1 exactly one argument required
-#      0 2 at most two arguments admissible
-#      2   at least two arguments required
-gsu_check_arg_count()
-{
-       ret=-$E_GSU_BAD_ARG_COUNT
-       if (($# == 2)); then # only num1 is given
-               result="at least $2 args required, $1 given"
-               (($1 < $2)) && return
-               ret=$GSU_SUCCESS
-               return
-       fi
-       # num1 and num2 given
-       result="need at least $2 args, $1 given"
-       (($1 < $2)) && return
-       result="need at most $3 args, $1 given"
-       (($1 > $3)) && return
-       ret=$GSU_SUCCESS
-}