1 files changed, 144 insertions, 0 deletions
diff --git a/atxec.c b/atxec.c
new file mode 100755
index 0000000..9432c56
--- /dev/null
+++ b/atxec.c
@@ -0,0 +1,144 @@
+/*
+ * atxec - run command expanding arguments from file or environment
+ *
+ * To the extent possible under law, Leah Neukirchen <leah@vuxu.org>
+ * has waived all copyright and related or neighboring rights to this work.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+// '''' => '
+
+// # line comment (space or beginning of line before #)
+// @file
+// @$ENV
+// @@argwithone@
+// fallbacks?
+
+#include <sys/stat.h>
+
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define MAXARGS 2048
+int narg;
+char *args[MAXARGS];
+
+static void
+push_arg(char *s)
+{
+	if (narg >= MAXARGS) {
+		fprintf(stderr, "atxec: too many arguments\n");
+		exit(111);
+	}
+
+	args[narg++] = s;
+}
+
+void
+arg_splice(char *s)
+{
+	char *beg;
+	char *t;
+
+	if (!s)
+		return;
+
+	while (1) {
+		while (isspace(*s) || *s == '#')
+			if (*s == '#')  /* skip line comment */
+				while (*s != '\n')
+					s++;
+			else
+				s++;
+
+		if (!*s)
+			break;
+
+		if (*s == '\'') {  /* rc-quoted string */
+			s++;
+			beg = t = s;
+
+			while (*s)
+				if (*s == '\'') {
+					*t++ = *s++;
+					if (*s == '\'') {
+						s++;
+					} else {
+						*--t = 0;
+						if (!*s)
+							beg--;
+						break;
+					}
+				} else {
+					*t++ = *s++;
+				}
+		} else {  /* bareword, may contain # without whitespace */
+			beg = s;
+			while (*s && !isspace(*s))
+				s++;
+		}
+
+		push_arg(beg);
+
+		if (*s) {
+			*s = 0;
+			s++;
+		} 
+	}
+}
+
+void
+file_splice(char *file)
+{
+	struct stat st;
+	char *s;
+
+	FILE *f = fopen(file, "rb");
+	if (!f)
+		return;   /* ignore file does not exist */
+
+	fstat(fileno(f), &st);
+
+	s = malloc(st.st_size + 1);
+	if (!s) {
+		fclose(f);
+		return;
+	}
+	fread(s, 1, st.st_size, f);
+	fclose(f);
+
+	s[st.st_size] = 0;
+
+	arg_splice(s);
+
+	/* leak string, args points into it! */
+}
+
+int
+main(int argc, char *argv[])
+{
+	if (argc == 1) {
+		fprintf(stderr, "usage\n");
+		return 1;
+	}
+
+	for (int i = 1; i < argc; i++)
+		if (argv[i][0] == '@') {
+			if (argv[i][1] == '@')
+				push_arg(argv[i]+1);
+			if (argv[i][1] == '$')
+				arg_splice(getenv(argv[i]+2));
+			else
+				file_splice(argv[i]+1);
+		} else {
+			push_arg(argv[i]);
+		}
+
+	execvp(args[0], args);
+
+	perror("argsplice: exec");
+	return 111;
+}