3505: Move helper scripts into crunchutil module. In run-command, added

[arvados.git] / crunch_scripts / crunchutil / subst.py

diff --git a/crunch_scripts/crunchutil/subst.py b/crunch_scripts/crunchutil/subst.py
new file mode 100644 (file)
index 0000000..b352688
--- /dev/null
+++ b/crunch_scripts/crunchutil/subst.py
@@ -0,0 +1,75 @@
+import os
+import glob
+
+def search(c):
+    DEFAULT = 0
+    DOLLAR = 1
+
+    i = 0
+    state = DEFAULT
+    start = None
+    depth = 0
+    while i < len(c):
+        if c[i] == '\\':
+            i += 1
+        elif state == DEFAULT:
+            if c[i] == '$':
+                state = DOLLAR
+                if depth == 0:
+                    start = i
+            elif c[i] == ')':
+                if depth == 1:
+                    return [start, i]
+                if depth > 0:
+                    depth -= 1
+        elif state == DOLLAR:
+            if c[i] == '(':
+                depth += 1
+            state = DEFAULT
+        i += 1
+    if depth != 0:
+        raise Exception("Substitution error, mismatched parentheses {}".format(c))
+    return None
+
+def sub_file(v):
+    return os.path.join(os.environ['TASK_KEEPMOUNT'], v)
+
+def sub_dir(v):
+    d = os.path.dirname(v)
+    if d == '':
+        d = v
+    return os.path.join(os.environ['TASK_KEEPMOUNT'], d)
+
+def sub_basename(v):
+    return os.path.splitext(os.path.basename(v))[0]
+
+def sub_glob(v):
+    l = glob.glob(v)
+    if len(l) == 0:
+        raise Exception("$(glob): No match on '%s'" % v)
+    else:
+        return l[0]
+
+default_subs = {"file ": sub_file,
+                "dir ": sub_dir,
+                "basename ": sub_basename,
+                "glob ": sub_glob}
+
+def do_substitution(p, c, subs=default_subs):
+    while True:
+        #print("c is", c)
+        m = search(c)
+        if m is not None:
+            v = do_substitution(p, c[m[0]+2 : m[1]])
+            var = True
+            for sub in subs:
+                if v.startswith(sub):
+                    r = subs[sub](v[len(sub):])
+                    var = False
+                    break
+            if var:
+                r = p[v]
+
+            c = c[:m[0]] + r + c[m[1]+1:]
+        else:
+            return c