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author | Martin Baulig <martin@src.gnome.org> | 1998-05-19 18:19:50 +0000 |
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committer | Martin Baulig <martin@src.gnome.org> | 1998-05-19 18:19:50 +0000 |
commit | 33cdc01c1db3a1cafaeb63e50247072b82ef49ea (patch) | |
tree | 765262671f242fc45d3504cc069636ced714e33b /sysdeps/linux/proclist.c | |
download | libgtop-33cdc01c1db3a1cafaeb63e50247072b82ef49ea.tar.gz |
Initial revision
Diffstat (limited to 'sysdeps/linux/proclist.c')
-rw-r--r-- | sysdeps/linux/proclist.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/sysdeps/linux/proclist.c b/sysdeps/linux/proclist.c new file mode 100644 index 00000000..39070689 --- /dev/null +++ b/sysdeps/linux/proclist.c @@ -0,0 +1,155 @@ +/* $Id$ */ + +/* Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc. + This file is part of the Gnome Top Library. + Contributed by Martin Baulig <martin@home-of-linux.org>, April 1998. + + The Gnome Top Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The Gnome Top Library 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <config.h> +#include <glibtop/xmalloc.h> +#include <glibtop/proclist.h> + +#include <sys/stat.h> +#include <unistd.h> +#include <dirent.h> +#include <ctype.h> + +static const unsigned long _glibtop_sysdeps_proclist = +(1 << GLIBTOP_PROCLIST_TOTAL) + (1 << GLIBTOP_PROCLIST_NUMBER) + +(1 << GLIBTOP_PROCLIST_SIZE); + +#define BLOCK_COUNT 256 +#define BLOCK_SIZE (BLOCK_COUNT * sizeof (unsigned)) + +/* Fetch list of currently running processes. + * + * The interface of this function is a little bit different from the others: + * buf->flags is only set if the call succeeded, in this case pids_chain, + * a list of the pids of all currently running processes is returned, + * buf->number is the number of elements of this list and buf->size is + * the size of one single element (sizeof (unsigned)). The total size is + * stored in buf->total. + * + * The calling function has to free the memory to which a pointer is returned. + * + * On error, NULL is returned and buf->flags is zero. */ + +unsigned * +glibtop_get_proclist__r (glibtop *server, glibtop_proclist *buf) +{ + DIR *proc; + struct dirent *entry; + char buffer [BUFSIZ]; + unsigned count, total, pid; + unsigned pids [BLOCK_COUNT], *pids_chain = NULL; + unsigned pids_size = 0, pids_offset = 0, new_size; + struct stat statb; + int len, i, ok; + + glibtop_init__r (&server); + + memset (buf, 0, sizeof (glibtop_proclist)); + + proc = opendir ("/proc"); + if (!proc) return NULL; + + /* read every every entry in /proc */ + + for (count = total = 0, entry = readdir (proc); entry; entry = readdir (proc)) { + ok = 1; len = strlen (entry->d_name); + + /* does it consist entirely of digits? */ + + for (i = 0; i < len; i++) + if (!isdigit (entry->d_name [i])) ok = 0; + if (!ok) continue; + + /* convert it in a number */ + + if (sscanf (entry->d_name, "%u", &pid) != 1) continue; + + /* is it really a directory? */ + + sprintf (buffer, "/proc/%d", pid); + + if (stat (buffer, &statb)) continue; + + if (!S_ISDIR (statb.st_mode)) continue; + + /* Fine. Now we first try to store it in pids. If this buffer is + * full, we copy it to the pids_chain. */ + + if (count >= BLOCK_COUNT) { + /* The following call to glibtop_realloc will be equivalent to + * glibtop_malloc if pids_chain is NULL. We just calculate the + * new size and copy pids to the beginning of the newly allocated + * block. */ + + new_size = pids_size + BLOCK_SIZE; + + pids_chain = glibtop_realloc__r (server, pids_chain, new_size); + + memcpy (pids_chain + pids_offset, pids, BLOCK_SIZE); + + pids_size = new_size; + + pids_offset += BLOCK_COUNT; + + count = 0; + } + + /* pids is now big enough to hold at least one single pid. */ + + pids [count++] = pid; + + total++; + } + + closedir (proc); + + /* count is only zero if an error occured (one a running Linux system, we + * only have at least one single process). */ + + if (!count) return NULL; + + /* The following call to glibtop_realloc will be equivalent to + * glibtop_malloc if pids_chain is NULL. We just calculate the + * new size and copy pids to the beginning of the newly allocated + * block. */ + + new_size = pids_size + count * sizeof (unsigned); + + pids_chain = glibtop_realloc__r (server, pids_chain, new_size); + + memcpy (pids_chain + pids_offset, pids, count * sizeof (unsigned)); + + pids_size = new_size; + + pids_offset += BLOCK_COUNT; + + /* Since everything is ok now, we can set buf->flags, fill in the remaining fields + and return pids_chain. */ + + buf->flags = _glibtop_sysdeps_proclist; + + buf->size = sizeof (unsigned); + buf->number = total; + + buf->total = total * sizeof (unsigned); + + return pids_chain; +} |