Make the other modules use error.c

Makefile

@@ -10,9 +10,9 @@ all : $(PROGRAMS)
 install : $(PROGRAMS)
 	cp $^ $(HOME)/bin/
 
-dlight : dlight.o env.o http.o rss.o lockfile.o filter.o cconf.o dlhist.o
-dlight-compile : compile.o env.o lockfile.o filter.o cconf.o
-dlight-read-config : read-config.o env.o cconf.o
+dlight : dlight.o env.o http.o rss.o lockfile.o filter.o cconf.o dlhist.o error.o
+dlight-compile : compile.o env.o lockfile.o filter.o cconf.o error.o
+dlight-read-config : read-config.o env.o cconf.o error.o
 
 dlight-% : %.o
 	$(CC) $(LDFLAGS) -o $@ $^

compile.c

@@ -27,12 +27,11 @@
 #include <errno.h>
 #include <ctype.h>
 #include "env.h"
+#include "error.h"
 #include "cconf.h"
 #include "lockfile.h"
 #include "filter.h"
 
-#define error(...) fprintf(stderr, "error: " __VA_ARGS__)
-
 #define isalias(x) (isalnum(x) || (x) == '-')
 
 #define MAXNAME 1024
@@ -252,8 +251,7 @@ static int parse_target(struct target *target) {
 	if (!alias)
 		return -1;
 	if (!alias[0] && !dest_table_nr) {
-		error("No destination found for target '%s'\n", src);
-		return -1;
+		return error("No destination found for target '%s'\n", src);
 	}
 
 	target->src = strdup(src);

dlight.c

@@ -3,14 +3,13 @@
 #include <string.h>
 #include <errno.h>
 #include "env.h"
+#include "error.h"
 #include "cconf.h"
 #include "dlhist.h"
 #include "filter.h"
 #include "http.h"
 #include "rss.h"
 
-#define error(...) fprintf(stderr, "error: " __VA_ARGS__)
-
 static void process_items(rss_t rss, struct target *t) {
 
 	int i;
@@ -29,8 +28,7 @@ static void process_items(rss_t rss, struct target *t) {
 
 			if (http_download_file(item.link, filter->dest) < 0 &&
 				errno != EEXIST) {
-				printf("download failed: %s\n",
-					strerror(errno));
+				error("download failed: %s\n", strerror(errno));
 				continue;
 			}
 

filter.c

@@ -21,17 +21,18 @@
 #include <pcre.h>
 #include <stdio.h>
 #include <string.h>
+#include "error.h"
 #include "filter.h"
 
 static inline pcre* compile(const char *pattern) {
 
-	const char *error;
+	const char *err;
 	int eoffset;
 	pcre *regex;
 
-	regex = pcre_compile(pattern, 0, &error, &eoffset, NULL);
+	regex = pcre_compile(pattern, 0, &err, &eoffset, NULL);
 	if (!regex) {
-		fprintf(stderr, "Error compiling expression\n");
+		error("Error compiling expression\n");
 		return NULL;
 	}
 
@@ -48,14 +49,14 @@ static inline int match(pcre *pcre, const char *subject) {
 
 int filter_check_syntax(const char *pattern) {
 
-	const char *error;
+	const char *err;
 	int eoffset;
 	pcre *regex;
 
-	regex = pcre_compile(pattern, 0, &error, &eoffset, NULL);
+	regex = pcre_compile(pattern, 0, &err, &eoffset, NULL);
 	if (!regex) {
-		fprintf(stderr, "filter: error in expression '%s': %s\n",
-			pattern, error);
+		error("filter: error in expression '%s': %s\n",
+			pattern, err);
 		return 0;
 	}
 	return 1;

http.c

@@ -25,6 +25,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include "error.h"
 #include "http.h"
 
 static char* strnstrr(const char *str, const char *needle, size_t size) {
@@ -109,7 +110,7 @@ static size_t write_cb(void *src, size_t smemb, size_t nmemb, void *data) {
 
 	dest->block = realloc(dest->block, dest->len + size);
 	if (dest->block == NULL) {
-		printf("out of memory\n");
+		error("out of memory\n");
 		return 0;
 	}
 	memcpy(dest->block + dest->len, src, size);
@@ -148,7 +149,7 @@ struct http_data* http_fetch_page(const char *url) {
 	res = curl_easy_perform(handle);
 
 	if (res != CURLE_OK) {
-		printf("curl: (%s) %s\n", url, curl_easy_strerror(res));
+		error("curl: (%s) %s\n", url, curl_easy_strerror(res));
 		goto error;
 	}
 
@@ -184,7 +185,7 @@ int http_download_file(const char *url, const char *dir) {
 	res = curl_easy_perform(handle);
 
 	if (res != CURLE_OK) {
-		printf("curl: (%s) %s\n", url, curl_easy_strerror(res));
+		error("curl: (%s) %s\n", url, curl_easy_strerror(res));
 		goto error;
 	}
 

lockfile.c

@@ -26,7 +26,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
-#include <errno.h>
+#include "error.h"
 #include "lockfile.h"
 
 #define locked(x) ((x)->fd >= 0)
@@ -95,13 +95,9 @@ int hold_lock(struct lockfile *lock, const char *filename, int force) {
 
 	lock->fd = open(lock->name, mask, 0600);
 	if (lock->fd < 0) {
-		if (errno == EEXIST) {
-			fprintf(stderr, "'%s' is locked\n", lock->name);
-		} else {
-			fprintf(stderr, "unable to create lockfile '%s'",
-				lock->name);
-		}
-		return -1;
+		return error(errno == EEXIST ?
+			"'%s' is locked\n" : "unable to create lockfile '%s'",
+			lock->name);
 	}
 	lock->next = active_locks;
 	active_locks = lock;

read-config.c

@@ -22,8 +22,9 @@
 #include <string.h>
 #include "cconf.h"
 #include "env.h"
+#include "error.h"
 
-static char *usage = "dlight-read-config [ <file> | -h ]\n";
+static char *usagestr = "dlight-read-config [ <file> | -h ]";
 
 int main(int argc, char **argv) {
 
@@ -33,8 +34,7 @@ int main(int argc, char **argv) {
 
 	if (argc > 1) {
 		if (!strcmp(argv[1], "-h")) {
-			fprintf(stderr, usage);
-			return 1;
+			usage(usagestr);
 		}
 		strncpy(file, argv[1], sizeof(file));
 	} else {