X-Git-Url: https://ruderich.org/simon/gitweb/?a=blobdiff_plain;f=lib.sh;h=5abd27898400e44bbaed2c14ec4a45ce80b8f480;hb=8348ecd5e6759f9551fac0431a45c3bdffc36956;hp=95c2fdf5c83efdc37212468d00e8f4c837ca7ac8;hpb=5b59dfd4b86ca165c34815c45dbed6eb45928038;p=config%2Fdotfiles.git

diff --git a/lib.sh b/lib.sh
index 95c2fdf..5abd278 100644
--- a/lib.sh
+++ b/lib.sh
@@ -23,10 +23,54 @@
 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() {
-    [ x`which $1 2>&1 | cut -c 1` = x/ ] || return 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/$1"; then
+                echo "$directory/$1"
+                return 0
+            fi
+        done
+
+        return 1
+    )
+}
+
+# Usage: cmd_i <cmd> ... <file>
+#
+# Run <cmd> with all arguments (including the last file) and write the result
+# to the temporary file <file>.tmp and then renamed that file to <file>. This
+# can't be done in-place (e.g. cmd <file >file) because it truncates the file.
+cmd_i() {
+    # Get last argument.
+    last=
+    for x; do
+        last="$x"
+    done
+
+    "$@" >"$last".tmp
+    mv "$last".tmp "$last"
+}
+
+# Usage: sed_i ... <file>
+#
+# sed -i is not compatible due to different implementations. See cmd_i.
+sed_i() {
+    cmd_i sed "$@"
 }
 
 # Print the current OS. The following OS are supported at the moment:
@@ -37,15 +81,15 @@ installed() {
 # - 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
+    elif test x`uname` = xDarwin; then
         echo darwin
-    elif [ x`uname` = xSunOS ]; then
+    elif test x`uname` = xSunOS; then
         echo sun
-    elif [ x`uname` = xFreeBSD ]; then
+    elif test x`uname` = xFreeBSD; then
         echo freebsd
     else
         echo unsupported OS! >&2
@@ -59,6 +103,8 @@ 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
@@ -71,14 +117,14 @@ link() {
 
     # 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
+    if ( test -f "$target" && test ! -h "$target" ) || \
+            ( test -s "$target" && test ! -h "$target" ); then
         echo "link(): target '$target' exists already and is no symbolic link!" >&2
         exit 1
     fi
 
     # Make sure the source exists (is file, directory or link).
-    if [ ! -f "$source" -a ! -d "$source" -a ! -h "$source" ]; then
+    if test ! -f "$source" && test ! -d "$source" && test ! -h "$source"; then
         echo "link(): source '$source' doesn't exist!" >&2
         exit 1
     fi
@@ -90,8 +136,6 @@ link() {
 
     # 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
@@ -108,7 +152,7 @@ warning() {
     # Display given options if there were any (Zsh has a problem with $options
     # as variable name).
     option=
-    if [ -n "$4" ]; then
+    if test -n "$4"; then
         option=" with options '$4'"
     fi
     # Write message to stdout.
@@ -138,11 +182,11 @@ generate() {
 
     # Set extension for the used commands. When cat is used $3 is used as
     # extension.
-    if [ x"$command" = xm4 ]; then
+    if test x"$command" = xm4; then
         extension=.m4
-    elif [ x"$command" = xawk -o x"$command" = xperl ]; then
+    elif test x"$command" = xawk -o x"$command" = xperl; then
         extension=.in
-    elif [ x"$command" = xcat ]; then
+    elif test 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.