read package info into snag

5 files changed, 107 insertions, 22 deletions

diff --git a/TODO b/TODO
index 37e4f77..40fac4b 100644
--- a/TODO
+++ b/TODO
@@ -1,2 +1,3 @@
 Things to come back to
- - [ ] Optional package info attributes
\ No newline at end of file
+ - [ ] Optional package info attributes
+ - [ ] better memory allocation strategies for snag (temporary, arena)
\ No newline at end of file
diff --git a/snag/getpkginfo.sh b/snag/getpkginfo.sh
deleted file mode 100755
index 0650740..0000000
--- a/snag/getpkginfo.sh
+++ /dev/null
@@ -1,17 +0,0 @@
-#!/bin/sh
-
-# reads a package description script and outputs the attributes in a format easy
-# for the snag program to read
-
-if [ -z "$1" ]; then
-    echo "Usage: $0 <description script>" >&2
-    exit 1
-fi
-
-# load the description script
-. $1
-
-# echo package properties
-echo ID   $pkg_id
-echo NAME $pkg_name
-echo DESC $pkg_desc
diff --git a/snag/main.c b/snag/main.c
index 9eacf33..10a5f86 100644
--- a/snag/main.c
+++ b/snag/main.c
@@ -1,12 +1,17 @@
 #include <stdio.h>
 #include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
-#define DESC_DIR "../snaggies"
+#define PKG_DB "../snaggies"
+#define PKG_INFO_CMD "./snagpkginfo.sh"
 
 typedef struct {
 	char* id;
 	char* name;
 	char* desc;
+	char* script_path;
 } package_info_t;
 
 void subcmd_install(char* pkgs[], size_t count);
@@ -25,9 +30,79 @@ void subcmd_install(char* pkgs[], size_t count) {
 	// install each package listed
 	for (int i = 0; i < count; ++i) {
 
-		char* package = pkgs[i];
-		printf("Installing '%s'\n", package);
+		char* pkgid = pkgs[i];
 
 		// load package description
+		package_info_t info;
+		if (load_package_info(&info, pkgid)) {
+			printf("Installing '%s'\n", info.name);
+		}
 	}
 }
+
+bool load_package_info(package_info_t* info, char* pkgid) {
+
+	// construct package description directory path and ensure it exists
+	size_t pkg_dir_len = strlen(PKG_DB) + strlen(pkgid) + 1;
+	char* pkg_dir = malloc(pkg_dir_len + 1);
+	snprintf(pkg_dir, pkg_dir_len + 1, "%s/%s", PKG_DB, pkgid);
+	if (access(pkg_dir, F_OK) != 0) {
+        fprintf(stderr, "Package '%s' not found in database\n", pkgid);
+		free(pkg_dir);
+		return false;
+    }
+
+	// construct package description script path and ensure it exists
+	size_t script_path_len = pkg_dir_len + strlen(pkgid) + 4;
+	info->script_path = malloc(script_path_len + 1);
+	snprintf(info->script_path, script_path_len + 1, "%s/%s.sh", pkg_dir, pkgid);
+	free(pkg_dir);
+	if (access(info->script_path, F_OK) != 0) {
+        fprintf(stderr, "Package '%s' broken, doesn't have description script\n", pkgid);
+		free(info->script_path);
+		return false;
+    }
+
+	// run getpkginfo script that outputs package attributes
+	size_t cmd_len = strlen(PKG_INFO_CMD) + script_path_len + 3;
+	char* cmd = malloc(cmd_len + 1);
+	snprintf(cmd, cmd_len + 1, "%s '%s'", PKG_INFO_CMD, info->script_path);
+	FILE* getinfo_fp = popen(cmd, "r");
+	if (getinfo_fp == NULL) {
+        perror("failed to popen getpkginfo");
+		exit(1); // fatal error
+    }
+
+	// go through each NULL delimited section of the output
+	size_t n = 0;
+	char* line = NULL;
+	ssize_t read;
+	while ((read = getdelim(&line, &n, '\0', getinfo_fp)) != -1) {
+		// read in property based on first attribute type character
+		char  atype  = line[0];
+		char* avalue = line+1;
+		switch (atype) {
+			case 'i':
+				// id
+				info->id = strdup(avalue);
+				break;
+			case 'n':
+				// name
+				info->name = strdup(avalue);
+				break;
+			case 'd':
+				// description
+				info->desc = strdup(avalue);
+				break;
+		}
+    }
+	free(line);
+
+	// close the getpkginfo process
+	if (pclose(getinfo_fp) != 0) {
+        perror("failed to pclose getpkginfo");
+		exit(1); // fatal error
+	}
+
+	return true;
+}
diff --git a/snag/readme.txt b/snag/readme.txt
index ef15404..d93431d 100644
--- a/snag/readme.txt
+++ b/snag/readme.txt
@@ -9,7 +9,7 @@
 
 `files`          - list the installed files of the specified package(s)
 `log`            - open your pager to the build log of the specified package
-`reason`         - list why this package is installed (manually installed, as a dependency, from a group)
+`why`            - list why this package is installed (manually installed, as a dependency, from a group)
 
 ## Terminology
 "Package Database"             - the directory containing package descriptions
@@ -29,3 +29,10 @@ Packages have the following attributes:
 `id` - the identifier name of the package. everything uses this
 `name` - the display name of package
 `desc` - the short description of the package
+
+## Interesting Features
+- switch between cli and tui mode mid run
+- build packages that aren't in the database
+
+## Developer Subcommands
+`validate` - check a package description and check for format errors or warnings
diff --git a/snag/snagpkginfo.sh b/snag/snagpkginfo.sh
new file mode 100755
index 0000000..bb80418
--- /dev/null
+++ b/snag/snagpkginfo.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+# reads a package description script and outputs the attributes in a format easy
+# for the snag program to read. it does not do any other validation, and should
+# not be used by other programs
+
+if [ -z "$1" ]; then
+    echo "Usage: $0 <description script>" >&2
+    exit 1
+fi
+
+# load the description script
+. $1
+
+# output package attributes (type char, value, null delimiter)
+echoatt() { [ -n "$2" ] && printf "$1$2\0"; }
+echoatt i "$pkg_id"
+echoatt n "$pkg_name"
+echoatt d "$pkg_desc"