X-Git-Url: https://ruderich.org/simon/gitweb/?p=config%2Fdotfiles.git;a=blobdiff_plain;f=lib.sh;h=05341537363b6e2bf19ed44df8bd50c3d184a175;hp=d9b14c50c8c1851ef1542ed9e2cd7ece5e003d3b;hb=9e4b2aff9242c3e72c714c3bf01c670b576e6627;hpb=28014a7a3978f84082fb7e979357e3ff56435887

diff --git a/lib.sh b/lib.sh
index d9b14c5..0534153 100644
--- a/lib.sh
+++ b/lib.sh
@@ -2,35 +2,130 @@
 #
 # Their setup.sh script sources this file.
 
+# Copyright (C) 2009-2018  Simon Ruderich
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 
 # csh gives the error "Unknown colorls variable `su'." when used with newer
 # options supported by Zsh or GNU ls.
 unset LS_COLORS
 
 
-# Check if the given program is installed. Returns 0 if it exists, 1
-# otherwise; so it can be used in if.
+# Check if the given program is installed. `type` is portable, `which` is not.
 installed() {
-    which $1 2>&1 | perl -ne 'if (not m{^/}) { exit 1 }'
+    type "$1" >/dev/null 2>&1
+}
+# Get the path of the given program. Thanks to Gilles on [1] (read on
+# 2013-03-10) for the PATH-walking idea. `which` is not portable and `type`
+# has no well-formed output format.
+#
+# [1]: http://unix.stackexchange.com/questions/4988/how-do-i-test-to-see-if-an-application-exists-in-path/4991
+installed_path() {
+    test -z "$1" && return 1
+
+    # Keep IFS change local.
+    (
+        IFS=:
+        # Walk PATH.
+        for directory in $PATH; do
+            if test -x "$directory/$1"; then
+                printf '%s\n' "$directory/$1"
+                return 0
+            fi
+        done
+
+        return 1
+    )
+}
+
+# Usage: cmd_i <cmd> ... <file>
+#
+# Run <cmd> with all arguments (including the last file) and write the result
+# to the temporary file <file>.tmp and then rename that file to <file>. This
+# can't be done in-place (e.g. cmd <file >file) because it truncates the file.
+cmd_i() {
+    # Get last argument.
+    last=
+    for x; do
+        last="$x"
+    done
+
+    "$@" >"$last".tmp
+    mv "$last".tmp "$last"
+}
+
+# Usage: sed_i ... <file>
+#
+# sed -i is not portable due to different implementations. See cmd_i.
+sed_i() {
+    cmd_i sed "$@"
+}
+grep_i() {
+    cmd_i grep "$@"
+}
+
+# Usage: perl_line_filter <cmd> ...
+#
+# Run the perl command cmd on each line before printing it.
+perl_line_filter() {
+    cmd="$1"
+    shift
+
+    # Can't use -pe because it uses <> which treats the arguments as files.
+    perl -e "use strict; use warnings; while (<STDIN>) { $cmd; print; }" "$@"
+}
+
+# Usage: simple_cpp <FIRST> <SECOND> .. -- <replacement-for-first> ...
+#
+# Replaces each FIRST (on word boundaries) with <replacement-for-first> like a
+# simple cpp replacement.
+simple_cpp() {
+    cmd='my $i = 0;'
+
+    for x; do
+        shift
+
+        if test x"$x" = x--; then
+            break
+        fi
+
+        cmd="$cmd s/\\b$x\\b/\$ARGV[\$i]/g; \$i++;"
+    done
+
+    perl_line_filter "$cmd" -- "$@"
 }
 
 # Print the current OS. The following OS are supported at the moment:
+#
 # - Debian (debian)
 # - Gentoo (gentoo)
-# - Mac OS X (darwin)
 # - Solaris/OpenSolaris (sun)
+# - FreeBSD (freebsd)
+#
 # If an unsupported OS is used an error is printed.
 os() {
-    if [ -f /etc/debian_version ]; then
+    if test -f /etc/debian_version; then
         echo debian
-    elif [ -f /etc/gentoo-release ]; then
+    elif test -f /etc/gentoo-release; then
         echo gentoo
-    elif [ x`uname` = xDarwin ]; then
-        echo darwin
-    elif [ x`uname` = xSunOS ]; then
+    elif test x"`uname`" = xSunOS; then
         echo sun
+    elif test x"`uname`" = xFreeBSD; then
+        echo freebsd
     else
-        echo unsupported OS! >&2
+        echo 'unsupported OS!' >&2
         return 1
     fi
 }
@@ -41,102 +136,83 @@ os() {
 # `./link.sh example ~/.examplerc` creates a symbolic link to example
 # (wherever it is located) in ~/ named .examplerc.
 link() {
+    local pwd base source target >/dev/null 2>&1 || true
+
     # Get all necessary paths.
     pwd=`pwd`
-    base=`echo "$2" | sed "s|\~|$HOME|"` # expand ~, some sh don't do it
+    base=`printf '%s' "$2" | sed "s|~|$HOME|"` # expand ~, some sh don't do it
     base=`dirname "$base"`
-    source=`echo "$pwd/$1" | sed "s|$base/||"`
+    source=`printf '%s' "$pwd/$1" | sed "s|$base/||"`
     target=`basename "$2"`
 
     # Go to the directory where the link is going to be created.
-    cd "$base"
+    cd "$base" || return 1
 
     # Abort if the target file exists and is no symbolic link. Prevents
     # overwriting real files.
-    if [ \( -f "$target" -a ! -h "$target" \) -o \
-         \( -s "$target" -a ! -h "$target" \) ]; then
-        echo "link(): target '$target' exists already and is no symbolic link!" >&2
+    if test -e "$target" && test ! -h "$target"; then
+        printf 'link(): target "%s" exists already and is no symbolic link!\n' \
+               "$target" >&2
         exit 1
     fi
 
-    # Make sure the source exists (is file, directory or link).
-    if [ ! -f "$source" -a ! -d "$source" -a ! -h "$source" ]; then
-        echo "link(): source '$source' doesn't exist!" >&2
+    # Make sure the source exists.
+    if test ! -e "$source"; then
+        printf 'link(): source "%s" does not exist!\n' "$source" >&2
         exit 1
     fi
 
     # Create the new symbolic link; remove the old one if necessary.
-    echo "link(): linking '$source' to '$target'"
+    printf 'link(): linking "%s" to "%s"\n' "$source" "$target"
     rm -f "$target"
     ln -s "$source" "$target"
 
     # Go back to the directory where we were before.
-    cd "$pwd"
-
-    unset pwd base source target
-}
-
-# Write a warning to $1 to make clear it should not be modified. $2 is the
-# source for the generated file. Also print a message to stdout that the file
-# $1 was generated from $2 using the command $3 with options $4.
-warning() {
-    echo "###################################" > $1
-    echo "# WARNING! DO NOT EDIT THIS FILE! #" >> $1
-    echo "###################################" >> $1
-    echo >> $1
-    echo "# It was generated from $2 on `date`." >> $1
-    echo >> $1
-
-    # Display given options if there were any (Zsh has a problem with $options
-    # as variable name).
-    option=
-    if [ -n "$4" ]; then
-        option=" with options '$4'"
-    fi
-    # Write message to stdout.
-    echo "$3: generating '$1' from '$2'$option"
-
-    unset option
+    cd "$pwd" || return 1
 }
 
-# Generate a file using several methods. A warning not to edit it is
-# automatically added to the created file and a message printed to stdout
-# through warning().
+# Generate a file from a source file using a given command. A warning not to
+# edit it is automatically added to the created file.
 #
-# The following commands are possible; the file extension for the source file
-# in brackets.
+# Usage: generate <file> <extension> <cmd..>
 #
-# - m4   (.m4): pipe $2.m4 through m4 then write it to $2
-# - awk  (.in): pipe $2.in through awk then write it to $2
-# - perl (.in): pipe $2.in through perl then write it to $2
-# - cat  ($3):  copy $2$3 to $2
+# If an empty extension is provided, the file is modified in-place (through a
+# temporary file).
 generate() {
+    local file      >/dev/null 2>&1 || true
+    local file_tmp  >/dev/null 2>&1 || true
+    local extension >/dev/null 2>&1 || true
+
     # Get command and target file.
-    command="$1"
-    file="$2"
-    # Remove arguments from list.
+    file="$1"
+    extension="$2"
     shift
     shift
 
-    # Set extension for the used commands. When cat is used $3 is used as
-    # extension.
-    if [ x"$command" = xm4 ]; then
-        extension=.m4
-    elif [ x"$command" = xawk -o x"$command" = xperl ]; then
-        extension=.in
-    elif [ x"$command" = xcat ]; then
-        extension="$1" # is $3 in reality, $1 because of shifting
-        shift
-    # Print a warning and exit if an unsupported command is used.
+    if test -z "$extension"; then
+        file_tmp="$file.tmp"
     else
-        echo "generate(): command '$command' not supported!" >&2
-        exit 1
+        # We only need this message if we generate a new file.
+        printf '%s: generating from "%s" (%s)\n' \
+            "$file" "$file$extension" "$1"
+
+        {
+            echo '###################################'
+            echo '# WARNING! DO NOT EDIT THIS FILE! #'
+            echo '###################################'
+            echo
+            printf '# It was generated from "%s" on %s.\n' \
+                "$file$extension" "`date`"
+            echo
+        } > "$file"
+
+        file_tmp="$file"
     fi
 
-    # Add warning to file and write a message to stdout.
-    warning "$file" "$file$extension" $command "$*"
     # Generate $file from $file$extension using the given command.
-    cat "$file$extension" | $command "$@" >> "$file"
+    "$@" <"$file$extension" >>"$file_tmp"
 
-    unset command file
+    if test -z "$extension"; then
+        mv "$file_tmp" "$file"
+    fi
 }