Remove github workflow

Before, strings such as @n@!_filename@@m wouldn't be parsed correctly
because of that '@@' in there.

.github/workflows/docker.yml

@@ -1,28 +0,0 @@
-name: Docker Hub
-
-on:
-  push:
-    branches: [ master ]
-  pull_request:
-    branches: [ master ]
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-
-      - name: Set login
-        uses: azure/docker-login@v1
-        with:
-          username: ${{ secrets.REGISTRY_USERNAME }}
-          password: ${{ secrets.REGISTRY_PASSWORD }}
-
-      - name: Build image
-        working-directory: ${{github.workspace}}
-        run: ./build.sh
-
-      - name: Push image
-        run: docker push natechoe/ncdg

Makefile

@@ -1,7 +1,7 @@
 SRC = $(wildcard src/*.c)
 OBJ = $(subst .c,.o,$(subst src,work,$(SRC)))
 LDFLAGS =
-CFLAGS := -O2 -pipe -Wall -Wpedantic -Wshadow -ansi
+CFLAGS := -pipe -Wall -Wpedantic -Wshadow -ansi -ggdb
 CFLAGS += -Isrc/include/
 INSTALLDIR := /usr/bin/
 OUT = ncdg

README.md

@@ -178,9 +178,8 @@ Turns into
 !dlrow olleH
 ```
 
-Things between an `@n` and `@m` tag get processed twice. A double escape char `@@`
-gets escaped into a single escape char `@`. Defining variables in a nest is
-illegal, so
+Things between an `@n` and `@m` tag get processed twice. Defining variables in a
+nest is illegal, so
 
 ```
 @n @@= dynamic_variable @$./generate_variable_value.sh@ @@ @m

src/include/config.h

@@ -6,6 +6,8 @@
 #define NOMINIFY_CHAR '&'
 #define SEPARATOR_CHAR ','
 #define SHELL_CHAR '$'
+#define NEST_START 'n'
+#define NEST_END 'm'
 
 #define ALLOW_SHELL
 

src/include/ncdgfile.h

@@ -0,0 +1,16 @@
+#ifndef HAVE_NCDGFILE
+#define HAVE_NCDGFILE
+
+#include <stdio.h>
+
+struct ncdgfile {
+	int (*putc)(struct ncdgfile *file, int c);
+	int (*puts)(struct ncdgfile *file, char *s);
+	void (*free)(struct ncdgfile *file);
+	void *handle;
+};
+
+struct ncdgfile *file2ncdg(FILE *file);
+struct ncdgfile *stringfile(void);
+
+#endif

src/ncdgfile.c

@@ -0,0 +1,74 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <strings.h>
+#include <ncdgfile.h>
+
+static int fileputc(struct ncdgfile *file, int c);
+static int fileputs(struct ncdgfile *file, char *s);
+static void filefree(struct ncdgfile *file);
+
+static int stringputc(struct ncdgfile *file, int c);
+static int stringputs(struct ncdgfile *file, char *s);
+static void stringfree(struct ncdgfile *file);
+
+struct ncdgfile *file2ncdg(FILE *file) {
+	struct ncdgfile *ret;
+	if ((ret = malloc(sizeof *ret)) == NULL) {
+		return NULL;
+	}
+	ret->putc = fileputc;
+	ret->puts = fileputs;
+	ret->free = filefree;
+	ret->handle = (void *) file;
+	return ret;
+}
+
+struct ncdgfile *stringfile(void) {
+	struct ncdgfile *ret;
+	if ((ret = malloc(sizeof *ret)) == NULL) {
+		goto error1;
+	}
+	if ((ret->handle = (void *) newstring()) == NULL) {
+		goto error2;
+	}
+	ret->putc = stringputc;
+	ret->puts = stringputs;
+	ret->free = stringfree;
+	return ret;
+error2:
+	free(ret);
+error1:
+	return NULL;
+}
+
+static int fileputc(struct ncdgfile *file, int c) {
+	return fputc(c, (FILE *) file->handle) == EOF ? -1 : 0;
+}
+
+static int fileputs(struct ncdgfile *file, char *s) {
+	return fputs(s, (FILE *) file->handle) == EOF ? -1 : 0;
+}
+
+static void filefree(struct ncdgfile *file) {
+	free(file);
+}
+
+static int stringputc(struct ncdgfile *file, int c) {
+	return appendchar((struct string *) file->handle, c) ? -1 : 0;
+}
+
+static int stringputs(struct ncdgfile *file, char *s) {
+	long i;
+	for (i = 0; s[i] != '\0'; ++i) {
+		if (appendchar((struct string *) file->handle, s[i])) {
+			return -1;
+		}
+	}
+	return 0;
+}
+
+static void stringfree(struct ncdgfile *file) {
+	freestring((struct string *) file->handle);
+	free(file);
+}

src/parse.c

@@ -11,6 +11,7 @@
 #include <parse.h>
 #include <vector.h>
 #include <strings.h>
+#include <ncdgfile.h>
 
 struct var {
 	struct string *var;
@@ -31,38 +32,44 @@ struct minstate {
 };
 
 static int expandfile(struct expandfile *ret, char *filename, int level);
-static int writefile(struct expandfile *file, FILE *out);
+static int writefile(struct expandfile *file, struct ncdgfile *out);
 static struct string *getstring(FILE *file, char end);
 static void initminstate(struct minstate *state);
-static void mputs(struct minstate *state, char *s, FILE *file);
-static void mputc(struct minstate *state, char c, FILE *file);
-static long putvar(long i, struct minstate *s, FILE *out,
+static void mputs(struct minstate *state, char *s, struct ncdgfile *file);
+static void mputc(struct minstate *state, char c, struct ncdgfile *file);
+static long putvar(long i, struct minstate *s, struct ncdgfile *out,
 		const struct string *file, const struct vector *vars);
 static int defvars(struct expandfile *expanded, char *filename);
+static long count_escapes(struct string *string);
 
 int parsefile(char *template, FILE *out) {
 	struct expandfile expanded;
 	int ret;
+	struct ncdgfile *ncdgout;
+	if ((ncdgout = file2ncdg(out)) == NULL) {
+		ret = 1;
+		goto error1;
+	}
 	expanded.data = newstring();
 	if (expanded.data == NULL) {
 		ret = 1;
-		goto error1;
+		goto error2;
 	}
 	expanded.vars = newvector(struct var);
 	if (expanded.vars == NULL) {
 		ret = 1;
-		goto error2;
+		goto error3;
 	}
 	if (defvars(&expanded, template)) {
 		ret = 1;
-		goto error3;
+		goto error4;
 	}
 	if (expandfile(&expanded, template, 0)) {
 		ret = 1;
-		goto error3;
+		goto error4;
 	}
-	ret = writefile(&expanded, out);
-error3:
+	ret = writefile(&expanded, ncdgout);
+error4:
 	{
 		int i;
 		for (i = 0; i < expanded.vars->len; ++i) {
@@ -73,15 +80,21 @@ error3:
 		}
 	}
 	freevector(expanded.vars);
-error2:
+error3:
 	freestring(expanded.data);
+error2:
+	ncdgout->free(ncdgout);
 error1:
 	return ret;
 }
 
-static int writefile(struct expandfile *file, FILE *out) {
+static int writefile(struct expandfile *file, struct ncdgfile *out) {
 	long i;
 	struct minstate s;
+	if (count_escapes(file->data) % 2 != 0) {
+		fputs("File or nest has an odd number of escape chars\n", stderr);
+		return 1;
+	}
 	initminstate(&s);
 	for (i = 0; i < file->data->len; ++i) {
 		if (file->data->data[i] == ESCAPE_CHAR) {
@@ -102,16 +115,16 @@ static int writefile(struct expandfile *file, FILE *out) {
 				for (++i; i < data->len; ++i) {
 					switch (data->data[i]) {
 					case '&':
-						fputs("&amp;", out);
+						out->puts(out, "&amp;");
 						break;
 					case ';':
-						fputs("&semi;", out);
+						out->puts(out, "&semi;");
 						break;
 					case '<':
-						fputs("&lt;", out);
+						out->puts(out, "&lt;");
 						break;
 					case '>':
-						fputs("&gt;", out);
+						out->puts(out, "&gt;");
 						break;
 					case ESCAPE_CHAR:
 						if (data->data[i + 1] != ESCAPE_CHAR)
@@ -119,7 +132,7 @@ static int writefile(struct expandfile *file, FILE *out) {
 						++i;
 						/* fallthrough */
 					default:
-						fputc(data->data[i], out);
+						out->putc(out, data->data[i]);
 						break;
 					}
 				}
@@ -134,7 +147,7 @@ autoescapeend:
 							break;
 						++i;
 					}
-					fputc(data->data[i], out);
+					out->putc(out, data->data[i]);
 				}
 				break;
 #ifdef ALLOW_SHELL
@@ -157,8 +170,81 @@ autoescapeend:
 				break;
 			}
 #endif
+			case NEST_START: {
+				struct ncdgfile *tmp;
+				struct string *buff;
+				struct expandfile nest;
+				int in_escape;
+				if ((buff = newstring()) == NULL) {
+					goto bufferror;
+				}
+
+				in_escape = 0;
+
+				++i;
+
+				/* read nest data into a string */
+				while (i < data->len) {
+					int c;
+					c = data->data[i++];
+					if (c != ESCAPE_CHAR) {
+						appendchar(buff, c);
+						continue;
+					}
+					if (in_escape) {
+						appendchar(buff, c);
+						in_escape = 0;
+						continue;
+					}
+					if (i >= data->len) {
+						break;
+					}
+					c = data->data[i++];
+					switch (c) {
+					case NEST_END:
+						goto got_nest;
+					default:
+						in_escape = 1;
+					case ESCAPE_CHAR:
+						appendchar(buff, ESCAPE_CHAR);
+						appendchar(buff, c);
+						break;
+					}
+				}
+				fputs("Unexpected EOF in nest\n", stderr);
+				return 1;
+got_nest:
+				--i;
+				if ((tmp = stringfile()) == NULL) {
+					goto bufferror;
+				}
+
+				/* first pass */
+				nest.data = buff;
+				nest.vars = file->vars;
+				if (writefile(&nest, tmp)) {
+					return 1;
+				}
+				freestring(buff);
+
+				/* second pass */
+				nest.data = (struct string *) tmp->handle;
+				if (writefile(&nest, out)) {
+					return 1;
+				}
+				tmp->free(tmp);
+
+				break;
+bufferror:
+				fputs("Failed to create temporary buffer while nesting\n", stderr);
+				return 1;
+			}
+			case NEST_END:
+				fputs("Error in expansion phase: Unmatched nest end char\n", stderr);
+				return 1;
 			default:
-				fprintf(stderr, "Error in expansion phase: Unknown escape %c%c\n", ESCAPE_CHAR, data->data[i]);
+				fprintf(stderr, "Error in expansion phase: Unknown escape '%c' (0x%x)\n",
+						data->data[i], data->data[i]);
 				return 1;
 			}
 		}
@@ -240,6 +326,39 @@ static int expandfile(struct expandfile *ret, char *filename, int level) {
 				freestring(inclname);
 				break;
 			}
+			case NEST_START: {
+				int origline = linenum;
+				appendchar(ret->data, ESCAPE_CHAR);
+				appendchar(ret->data, NEST_START);
+				for (;;) {
+					c = fgetc(file);
+					if (c == EOF) {
+						goto no_nest_end;
+					}
+					if (c != ESCAPE_CHAR) {
+						appendchar(ret->data, c);
+						continue;
+					}
+					appendchar(ret->data, c);
+					c = fgetc(file);
+					if (c == NEST_END) {
+						appendchar(ret->data, c);
+						break;
+					}
+					ungetc(c, file);
+					do {
+						c = fgetc(file);
+						appendchar(ret->data, c);
+					} while (c != ESCAPE_CHAR);
+				}
+				break;
+no_nest_end:
+				fprintf(stderr, "Line %d: Unmatched nest start char\n", origline);
+				goto error;
+			}
+			case NEST_END:
+				fprintf(stderr, "Line %d: Unmatched nest end\n", linenum);
+				goto error;
 			default:
 				fprintf(stderr, "Line %d: Invalid escape %c\n",
 						linenum, c);
@@ -292,25 +411,25 @@ static void initminstate(struct minstate *state) {
 	memset(state, 0, sizeof *state);
 }
 
-static void mputs(struct minstate *state, char *s, FILE *file) {
+static void mputs(struct minstate *state, char *s, struct ncdgfile *file) {
 	int i;
 	for (i = 0; s[i] != '\0'; ++i)
 		mputc(state, s[i], file);
 }
 
-static void mputc(struct minstate *state, char c, FILE *file) {
+static void mputc(struct minstate *state, char c, struct ncdgfile *file) {
 	if (isspace(c))
 		state->isspace = 1;
 	else {
 		if (!state->ignore && state->isspace && c != '>')
-			fputc(' ', file);
-		fputc(c, file);
+			file->putc(file, ' ');
+		file->putc(file, c);
 		state->ignore = c == '<';
 		state->isspace = 0;
 	}
 }
 
-static long putvar(long i, struct minstate *s, FILE *out,
+static long putvar(long i, struct minstate *s, struct ncdgfile *out,
 		const struct string *file, const struct vector *vars) {
 	long start;
 	for (;;) {
@@ -363,3 +482,14 @@ error2:
 error1:
 	return 1;
 }
+
+static long count_escapes(struct string *string) {
+	long i, ret;
+	ret = 0;
+	for (i = 0; i < string->len; ++i) {
+		if (string->data[i] == ESCAPE_CHAR) {
+			++ret;
+		}
+	}
+	return ret;
+}