strace-log-merge: cleanup

* strace-log-merge: Redirect usage to stderr, make the check
for numeric suffix simpler.

diff --git a/strace-log-merge b/strace-log-merge
index a8efb9df92ce95c78b9d1d663c6983cabc07dd6e..9dc03b89c8ebf9975c470cb84b675d6de92e75f0 100755 (executable)
--- a/strace-log-merge
+++ b/strace-log-merge
@@ -1,46 +1,33 @@
 #!/bin/sh
 
 if test $# = 0; then
-       echo "Usage: ${0##*/} STRACE_LOG"
-       echo
-       echo "\
+       cat >&2 <<__EOF__
+Usage: ${0##*/} STRACE_LOG
+
 Finds all STRACE_LOG.PID files, adds PID prefix to every line,
 then combines and sorts them, and prints result to standard output.
 
 It is assumed that STRACE_LOGs were produced by strace with -tt[t]
-option which prints timestamps (otherwise sorting won't do any good).\
-"
-       exit
+option which prints timestamps (otherwise sorting won't do any good).
+__EOF__
+       exit 1
 fi
 
-is_numeric() {
-       # Remove digits. If something remains,
-       # then $1 is not a number
-
-       u=$1
-       test "$u" || return 1 # "" is not a number
-
-       while true; do
-               v=${u#[0123456789]} # remove one digit
-               test "$v" || return 0 # we removed all chars. ok
-               test "$v" = "$u" && return 1 # we have non-digit. bad
-               u=$v
-       done
-}
-
 logfile=$1
 pfxlen=${#1}
 
 for file in "$logfile".*; do
+       [ -f "$file" ] || continue
        suffix=${file:1+$pfxlen}
-       is_numeric "$suffix" || {
+       [ "$suffix" -gt 0 ] 2> /dev/null || {
                echo "Skipped file '$file' (bad suffix)" >&2
                continue
        }
        pid=$(printf "%-5s" $suffix)
-       # Some strace logs have last line which is not '\n' terminated.
-       # 's/$/\n/' adds extra newlines to every line.
+       # Some strace logs have last line which is not '\n' terminated,
+       # so add extra newline to every file.
        # grep -v '^$' removes empty lines which may result.
-       sed -e "s/^/$pid /" -e 's/$/\n/' <"$file"
+       sed "s/^/$pid /" < "$file"
+       echo
 done \
 | grep -v '^$' | sort -k2