commit c75cbff329e706e955d8f3e353628c7d950b6ca5
Author: Nero <41307858+nero@users.noreply.github.com>
Date:   Sun Sep 11 14:51:37 2022 +0000

    Finalize project

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..9ff241a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,10 @@
+PROGS = sh_quote
+CFLAGS = -std=c99 -pedantic
+
+default: $(PROGS)
+
+test: $(PROGS)
+	./test_sh_quote
+
+clean:
+	rm -f $(PROGS)
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..265b5e7
--- /dev/null
+++ b/README.md
@@ -0,0 +1,39 @@
+# Shell quoting util
+
+This tool was made to handle a specific edge case in shell scripting.
+
+When you want to supply a command to some tool as a shell string, but you only have it as already expanded array.
+
+This doesn't work as expected because `$@` is expanded, ending up as multiple arguments to `su`:
+
+```
+su -c "$@"
+```
+
+This does work as expected:
+
+```
+su -c "$(sh_quote "$@")"
+```
+
+Because all arguments must be relayed, `-h` or `--help` cannot be taken into account, so there is no helptext.
+
+When no arguments are given, it returns without producing any output.
+
+# Error messages
+
+None. This program cannot fail.
+
+If stdout is not writable, no sensible output will be generated.
+
+If `$0` is not set, no output will be generated.
+
+# Building
+
+Run `make`.
+
+# Testing
+
+Run `make test`
+
+The test script can also run on arbitrary programs: `./run_sh_quote /path/to/other_program`.
diff --git a/sh_quote.c b/sh_quote.c
new file mode 100644
index 0000000..f94ddef
--- /dev/null
+++ b/sh_quote.c
@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <string.h>
+
+int main(int argc, char** argv) {
+  unsigned int i;
+  char* p;
+  char* delim = "'";
+  for (i = 1; i < argc; i++) {
+    if (i > 1) putchar(' ');
+    p = argv[i];
+
+    printf("%s", delim);
+    while(*p != '\0') {
+      if (p[0] == '\'') {
+        printf("%s\\'%s", delim, delim);
+        p++;
+        continue;
+      }
+      if (p[0] == '\\') putchar('\\');
+      putchar((p++)[0]);
+    }
+    printf("%s", delim);
+  }
+  putchar('\n');
+  return 0;
+}
diff --git a/test_sh_quote b/test_sh_quote
new file mode 100755
index 0000000..4d42108
--- /dev/null
+++ b/test_sh_quote
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+#!/bin/sh
+PROG=${1:-./sh_quote}
+
+run_test() {
+  r=$($PROG "$2"|sed 's/^ *//;s/ *$//')
+  if test "$r" == "$3"; then
+    echo PASS "$1"
+  else
+    echo FAIL "$1"
+    printf "Expected: %s\nGot: %s\n" "$3" "$r"
+  fi
+}
+
+run_test empty "" "''"
+run_test whitespace "Foo Bar" "'Foo Bar'"
+run_test quote "Foo'Bar" "'Foo'\''Bar'"
+run_test newline "Foo
+Bar" "'Foo
+Bar'"
+run_test trailing_space "Foobar " "'Foobar '"