I just wrote up a simple pidof applet, closing bug #1197

-Erik

Changelog

@@ -13,6 +13,7 @@
     New Applets:
 	* David McCullough <davidm@lineo.com> -- modprobe
 	* Vladimir Oleynik -- traceroute
+	* Erik Andersen -- pidof
 
     New Scripts:
 	* David Schleef, Erik Andersen, Stuart Hughes -- depmod.pl

Config.h

@@ -82,6 +82,7 @@
 #define BB_MV
 //#define BB_NC
 //#define BB_NSLOOKUP
+#define BB_PIDOF
 //#define BB_PING
 //#define BB_PIVOT_ROOT
 #define BB_POWEROFF

applets.h

@@ -284,6 +284,9 @@
 #ifdef BB_NSLOOKUP
 	APPLET(nslookup, nslookup_main, _BB_DIR_USR_BIN)
 #endif
+#ifdef BB_PIDOF
+	APPLET(pidof, pidof_main, _BB_DIR_BIN)
+#endif
 #ifdef BB_PING
 	APPLET(ping, ping_main, _BB_DIR_BIN)
 #endif

applets/usage.h

@@ -1190,6 +1190,14 @@
 	"Name:       debian\n" \
 	"Address:    127.0.0.1\n" 
 
+#define pidof_trivial_usage \
+	"process-name [process-name ...]"
+#define pidof_full_usage \
+	"Lists the PIDs of all processes with names that match the names on the command line"
+#define pidof_example_usage \
+	"$ pidof init\n" \
+	"1\n"
+
 #ifndef BB_FEATURE_FANCY_PING
 #define ping_trivial_usage "host"
 #define ping_full_usage    "Send ICMP ECHO_REQUEST packets to network hosts"

include/applets.h

@@ -284,6 +284,9 @@
 #ifdef BB_NSLOOKUP
 	APPLET(nslookup, nslookup_main, _BB_DIR_USR_BIN)
 #endif
+#ifdef BB_PIDOF
+	APPLET(pidof, pidof_main, _BB_DIR_BIN)
+#endif
 #ifdef BB_PING
 	APPLET(ping, ping_main, _BB_DIR_BIN)
 #endif

include/usage.h

@@ -1190,6 +1190,14 @@
 	"Name:       debian\n" \
 	"Address:    127.0.0.1\n" 
 
+#define pidof_trivial_usage \
+	"process-name [process-name ...]"
+#define pidof_full_usage \
+	"Lists the PIDs of all processes with names that match the names on the command line"
+#define pidof_example_usage \
+	"$ pidof init\n" \
+	"1\n"
+
 #ifndef BB_FEATURE_FANCY_PING
 #define ping_trivial_usage "host"
 #define ping_full_usage    "Send ICMP ECHO_REQUEST packets to network hosts"

pidof.c

@@ -0,0 +1,79 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * pidof implementation for busybox
+ *
+ * Copyright (C) 2001 by Lineo, inc.
+ * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+#include <signal.h>
+#include <ctype.h>
+#include <string.h>
+#include <unistd.h>
+#include "busybox.h"
+
+
+extern int pidof_main(int argc, char **argv)
+{
+	int opt;
+
+
+	/* do normal option parsing */
+	while ((opt = getopt(argc, argv, "ne:f:")) > 0) {
+		switch (opt) {
+#if 0
+			case 'g':
+				break;
+			case 'e':
+				break;
+#endif
+			default:
+				show_usage();
+		}
+	}
+
+	/* if we didn't get a process name, then we need to choke and die here */
+	if (argv[optind] == NULL)
+		show_usage();
+
+	/* Looks like everything is set to go. */
+	while(optind < argc) {
+		pid_t* pidList;
+
+		pidList = find_pid_by_name( argv[optind]);
+		if (!pidList || *pidList<=0) {
+			break;
+		}
+
+		for(; pidList && *pidList!=0; pidList++) {
+			printf("%ld ", (long)*pidList);
+		}
+		/* Note that we don't bother to free the memory
+		 * allocated in find_pid_by_name().  It will be freed
+		 * upon exit, so we can save a byte or two */
+		optind++;
+	}
+	printf("\n");
+
+	return EXIT_SUCCESS;
+}

procps/pidof.c

@@ -0,0 +1,79 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * pidof implementation for busybox
+ *
+ * Copyright (C) 2001 by Lineo, inc.
+ * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+#include <signal.h>
+#include <ctype.h>
+#include <string.h>
+#include <unistd.h>
+#include "busybox.h"
+
+
+extern int pidof_main(int argc, char **argv)
+{
+	int opt;
+
+
+	/* do normal option parsing */
+	while ((opt = getopt(argc, argv, "ne:f:")) > 0) {
+		switch (opt) {
+#if 0
+			case 'g':
+				break;
+			case 'e':
+				break;
+#endif
+			default:
+				show_usage();
+		}
+	}
+
+	/* if we didn't get a process name, then we need to choke and die here */
+	if (argv[optind] == NULL)
+		show_usage();
+
+	/* Looks like everything is set to go. */
+	while(optind < argc) {
+		pid_t* pidList;
+
+		pidList = find_pid_by_name( argv[optind]);
+		if (!pidList || *pidList<=0) {
+			break;
+		}
+
+		for(; pidList && *pidList!=0; pidList++) {
+			printf("%ld ", (long)*pidList);
+		}
+		/* Note that we don't bother to free the memory
+		 * allocated in find_pid_by_name().  It will be freed
+		 * upon exit, so we can save a byte or two */
+		optind++;
+	}
+	printf("\n");
+
+	return EXIT_SUCCESS;
+}

usage.h

@@ -1190,6 +1190,14 @@
 	"Name:       debian\n" \
 	"Address:    127.0.0.1\n" 
 
+#define pidof_trivial_usage \
+	"process-name [process-name ...]"
+#define pidof_full_usage \
+	"Lists the PIDs of all processes with names that match the names on the command line"
+#define pidof_example_usage \
+	"$ pidof init\n" \
+	"1\n"
+
 #ifndef BB_FEATURE_FANCY_PING
 #define ping_trivial_usage "host"
 #define ping_full_usage    "Send ICMP ECHO_REQUEST packets to network hosts"