Improve test framework: tfw_cat --hexdump, TFWSTDOUT

Add -h|--hexdump option to tfw_cat() and fix faulty logic in tfw_cat()
-v option wof files not ending in \n (newline)

Add TFWSTDOUT and TFWSTDERR env vars set by execute() with absolute
path names of files containing stdout and stderr respectively (as an
alternative to using replayStdout() and replayStderr()).

testframework.sh

@@ -869,7 +869,7 @@ tfw_cmp_version() {
 # context that stdout (fd 1) is redirected.
 tfw_cat() {
    local header=
-   local show_nonprinting=
+   local -a show=(cat)
    for file; do
       case $file in
       --header=*)
@@ -877,15 +877,19 @@ tfw_cat() {
          continue
          ;;
       -v|--show-nonprinting)
-         show_nonprinting=-v
+         show=(cat -v)
+         continue
+         ;;
+      -h|--hexdump)
+         show=(hd '</dev/null')
          continue
          ;;
       --stdout)
-         file="$_tfw_process_tmp/stdout"
+         file="${TFWSTDOUT?}"
          header="${header:-stdout of ($executed)}"
          ;;
       --stderr)
-         file="$_tfw_process_tmp/stderr"
+         file="${TFWSTDERR?}"
          header="${header:-stderr of ($executed)}"
          ;;
       *)
@@ -894,17 +898,19 @@ tfw_cat() {
       esac
       local missing_nl=
       tfw_log "#----- $header -----"
-      cat $show_nonprinting "$file" >&$_tfw_log_fd
+      eval "${show[@]}" "$file" >&$_tfw_log_fd
-      if [ "$(tail -1c "$file")" != "$newline" ]; then
+      if [ "${show[0]}" = cat -a "$(tail -1c "$file" | wc -l)" -eq 0 ]; then
          echo >&$_tfw_log_fd
          missing_nl=" (no newline at end)"
       fi
       tfw_log "#-----$missing_nl"
       header=
-      show_nonprinting=
+      show=(cat)
    done
 }
 
+# Format the standard input into multi columns within an output width set by the
+# COLUMNS env var.
 tfw_multicolumn() {
    $AWK '
       function pad(s, n) {
@@ -965,11 +971,11 @@ assertRealTime() {
 }
 
 replayStdout() {
-   cat $_tfw_tmp/stdout
+   cat ${TFWSTDOUT?}
 }
 
 replayStderr() {
-   cat $_tfw_tmp/stderr
+   cat ${TFWSTDERR?}
 }
 
 assertStdoutIs() {
@@ -1147,8 +1153,10 @@ _tfw_execute() {
       ulimit -S -c unlimited
       rm -f core
    fi
+   export TFWSTDOUT="$_tfw_process_tmp/stdout"
+   export TFWSTDERR="$_tfw_process_tmp/stderr"
    {
-      time -p "$_tfw_executable" "$@" >"$_tfw_process_tmp/stdout" 2>"$_tfw_process_tmp/stderr"
+      time -p "$_tfw_executable" "$@" >"$TFWSTDOUT" 2>"$TFWSTDERR"
    } 2>"$_tfw_process_tmp/times" &
    local subshell_pid=$!
    local timer_pid=
@@ -1194,7 +1202,6 @@ _tfw_execute() {
    # Deal with exit status.
    if [ -n "$_tfw_opt_exit_status" ]; then
       _tfw_message="exit status ($_tfw_exitStatus) of ($executed) is $_tfw_opt_exit_status"
-      _tfw_dump_stderr_on_fail=true
       _tfw_assert [ "$_tfw_exitStatus" -eq "$_tfw_opt_exit_status" ] || _tfw_failexit || return $?
       $_tfw_assert_noise && tfw_log "# assert $_tfw_message"
    else