gawk

commit fffd975b08d08b6e98a0cd262310fdb2009f1623
parent f5df3aa9a53ef4f7951a3a639aa33960eb8e6308
Author: Jacob R. Edwards <jacobouno@protonmail.com>
Date:   Wed,  6 Jan 2021 21:10:15 -0800

Add command negation

If a command is prefixed with `!' (configurable in config.h) the
PASS and NEXT values are inverted.

I was going to implement this within ftype() where I thought it
would be useful, but that makes no sense, might as aswell vastly
improve every command by adding it higher up.

Diffstat:
M
config.def.h
 | 
3
+++
M
gawk.h
 | 
3
++-
M
main.c
 | 
12
+++++++++++-

3 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/config.def.h b/config.def.h
@@ -3,6 +3,9 @@
 /* how long to wait for response in ms */
 static int const timeout = 5 * 1000;
 
+/* character used to negate commands */
+static char const negate = '!';
+
 /* default address if arguments are ommited */
 static char *default_address[] = {
 	/* path, host, port */
diff --git a/gawk.h b/gawk.h
@@ -21,7 +21,7 @@ enum gphitem { GI_INFO, GI_PATH, GI_HOST, GI_PORT, GI_PLUS, GI_NULL };
 
 /* command and pipeline status */
 enum cstatus { ERROR = -1, OK, UNWIND };
-enum pstatus { NEXT = -2, FAIL, PASS };
+enum pstatus { FAIL = -2, NEXT, PASS };
 
 typedef int (command)(int, char **, int, char **);
 
@@ -29,6 +29,7 @@ struct command {
 	char *argv[MY_ARGV_MAX];
 	command *f;
 	int argc;
+	int negate;
 };
 
 struct bind {
diff --git a/main.c b/main.c
@@ -274,8 +274,12 @@ runpipe(struct command *cmds, int *indexes, int count, char **item)
 
 	for (i = 0; i < count; ++i) {
 		r = cmds[i].f(cmds[i].argc, cmds[i].argv, indexes[i]++, item);
-		if (r != PASS)
+		if (r != PASS && r != NEXT)
 			return r;
+		if (cmds[i].negate)
+			r = !r;
+		if (r)
+			return NEXT;
 	}
 	return PASS;
 }
@@ -327,6 +331,12 @@ execute(char const *cache, char *input, int depth, char **addr)
 				warn(0, "command %d: Empty command.", i);
 			return ERROR;
 		}
+		if (cmds[i].argv[0][0] != negate) {
+			cmds[i].negate = 0;
+		} else {
+			cmds[i].negate = 1;
+			cmds[i].argv[0]++;
+		}
 	}
 
 	for (i = 0; i < nbufs; ++i) {