busybox/applets/applet_tables.c

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2007-11-28 12:19:42 +05:30
/* vi: set sw=4 ts=4: */
/*
* Applet table generator.
* Runs on host and produces include/applet_tables.h
*
* Copyright (C) 2007 Denys Vlasenko <vda.linux@googlemail.com>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
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*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <limits.h>
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#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <ctype.h>
#undef ARRAY_SIZE
#define ARRAY_SIZE(x) ((unsigned)(sizeof(x) / sizeof((x)[0])))
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#include "../include/autoconf.h"
#include "../include/applet_metadata.h"
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struct bb_applet {
const char *name;
const char *main;
enum bb_install_loc_t install_loc;
enum bb_suid_t need_suid;
/* true if instead of fork(); exec("applet"); waitpid();
* one can do fork(); exit(applet_main(argc,argv)); waitpid(); */
unsigned char noexec;
/* Even nicer */
/* true if instead of fork(); exec("applet"); waitpid();
* one can simply call applet_main(argc,argv); */
unsigned char nofork;
};
/* Define struct bb_applet applets[] */
#include "../include/applets.h"
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enum { NUM_APPLETS = ARRAY_SIZE(applets) };
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static int cmp_name(const void *a, const void *b)
{
const struct bb_applet *aa = a;
const struct bb_applet *bb = b;
return strcmp(aa->name, bb->name);
}
static int str_isalnum_(const char *s)
{
while (*s) {
if (!isalnum(*s) && *s != '_')
return 0;
s++;
}
return 1;
}
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int main(int argc, char **argv)
{
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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int i, j;
char tmp1[PATH_MAX], tmp2[PATH_MAX];
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// In find_applet_by_name(), before linear search, narrow it down
// by looking at N "equidistant" names. With ~350 applets:
// KNOWN_APPNAME_OFFSETS cycles
// 0 9057
// 2 4604 + ~100 bytes of code
// 4 2407 + 4 bytes
// 8 1342 + 8 bytes
// 16 908 + 16 bytes
// 32 884 + 32 bytes
// With 8, int16_t applet_nameofs[] table has 7 elements.
int KNOWN_APPNAME_OFFSETS = 8;
// With 128 applets we do two linear searches, with 1..7 strcmp's in the first one
// and 1..16 strcmp's in the second. With 256 apps, second search does 1..32 strcmp's.
if (NUM_APPLETS < 128)
KNOWN_APPNAME_OFFSETS = 4;
if (NUM_APPLETS < 32)
KNOWN_APPNAME_OFFSETS = 0;
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qsort(applets, NUM_APPLETS, sizeof(applets[0]), cmp_name);
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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if (!argv[1])
return 1;
snprintf(tmp1, PATH_MAX, "%s.%u.new", argv[1], (int) getpid());
i = open(tmp1, O_WRONLY | O_TRUNC | O_CREAT, 0666);
if (i < 0)
return 1;
dup2(i, 1);
/* Keep in sync with include/busybox.h! */
printf("/* This is a generated file, don't edit */\n\n");
printf("#define NUM_APPLETS %u\n", NUM_APPLETS);
if (NUM_APPLETS == 1) {
printf("#define SINGLE_APPLET_STR \"%s\"\n", applets[0].name);
printf("#define SINGLE_APPLET_MAIN %s_main\n", applets[0].main);
}
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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printf("#define KNOWN_APPNAME_OFFSETS %u\n\n", KNOWN_APPNAME_OFFSETS);
if (KNOWN_APPNAME_OFFSETS > 0) {
int ofs, offset[KNOWN_APPNAME_OFFSETS], index[KNOWN_APPNAME_OFFSETS];
for (i = 0; i < KNOWN_APPNAME_OFFSETS; i++)
index[i] = i * NUM_APPLETS / KNOWN_APPNAME_OFFSETS;
ofs = 0;
for (i = 0; i < NUM_APPLETS; i++) {
for (j = 0; j < KNOWN_APPNAME_OFFSETS; j++)
if (i == index[j])
offset[j] = ofs;
ofs += strlen(applets[i].name) + 1;
}
/* If the list of names is too long refuse to proceed */
if (ofs > 0xffff)
return 1;
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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printf("const uint16_t applet_nameofs[] ALIGN2 = {\n");
for (i = 1; i < KNOWN_APPNAME_OFFSETS; i++)
printf("%d,\n", offset[i]);
printf("};\n\n");
}
//printf("#ifndef SKIP_definitions\n");
printf("const char applet_names[] ALIGN1 = \"\"\n");
for (i = 0; i < NUM_APPLETS; i++) {
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printf("\"%s\" \"\\0\"\n", applets[i].name);
// if (MAX_APPLET_NAME_LEN < strlen(applets[i].name))
// MAX_APPLET_NAME_LEN = strlen(applets[i].name);
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}
printf(";\n\n");
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for (i = 0; i < NUM_APPLETS; i++) {
if (str_isalnum_(applets[i].name))
printf("#define APPLET_NO_%s %d\n", applets[i].name, i);
}
printf("\n");
printf("#ifndef SKIP_applet_main\n");
printf("int (*const applet_main[])(int argc, char **argv) = {\n");
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for (i = 0; i < NUM_APPLETS; i++) {
printf("%s_main,\n", applets[i].main);
}
printf("};\n");
printf("#endif\n\n");
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#if ENABLE_FEATURE_PREFER_APPLETS \
|| ENABLE_FEATURE_SH_STANDALONE \
|| ENABLE_FEATURE_SH_NOFORK
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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printf("const uint8_t applet_flags[] ALIGN1 = {\n");
i = 0;
while (i < NUM_APPLETS) {
int v = applets[i].nofork + (applets[i].noexec << 1);
if (++i < NUM_APPLETS)
v |= (applets[i].nofork + (applets[i].noexec << 1)) << 2;
if (++i < NUM_APPLETS)
v |= (applets[i].nofork + (applets[i].noexec << 1)) << 4;
if (++i < NUM_APPLETS)
v |= (applets[i].nofork + (applets[i].noexec << 1)) << 6;
printf("0x%02x,\n", v);
i++;
}
printf("};\n\n");
#endif
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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#if ENABLE_FEATURE_SUID
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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printf("const uint8_t applet_suid[] ALIGN1 = {\n");
i = 0;
while (i < NUM_APPLETS) {
int v = applets[i].need_suid; /* 2 bits */
if (++i < NUM_APPLETS)
v |= applets[i].need_suid << 2;
if (++i < NUM_APPLETS)
v |= applets[i].need_suid << 4;
if (++i < NUM_APPLETS)
v |= applets[i].need_suid << 6;
printf("0x%02x,\n", v);
i++;
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}
printf("};\n\n");
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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#endif
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#if ENABLE_FEATURE_INSTALLER
printf("const uint8_t applet_install_loc[] ALIGN1 = {\n");
i = 0;
while (i < NUM_APPLETS) {
int v = applets[i].install_loc; /* 3 bits */
if (++i < NUM_APPLETS)
v |= applets[i].install_loc << 4; /* 3 bits */
printf("0x%02x,\n", v);
i++;
}
printf("};\n");
#endif
//printf("#endif /* SKIP_definitions */\n");
// printf("\n");
// printf("#define MAX_APPLET_NAME_LEN %u\n", MAX_APPLET_NAME_LEN);
if (argv[2]) {
FILE *fp;
char line_new[80];
// char line_old[80];
sprintf(line_new, "#define NUM_APPLETS %u\n", NUM_APPLETS);
// line_old[0] = 0;
// fp = fopen(argv[2], "r");
// if (fp) {
// fgets(line_old, sizeof(line_old), fp);
// fclose(fp);
// }
// if (strcmp(line_old, line_new) != 0) {
snprintf(tmp2, PATH_MAX, "%s.%u.new", argv[2], (int) getpid());
fp = fopen(tmp2, "w");
if (!fp)
return 1;
fputs(line_new, fp);
if (fclose(fp))
return 1;
// }
}
if (fclose(stdout))
return 1;
if (rename(tmp1, argv[1]))
return 1;
if (rename(tmp2, argv[2]))
return 1;
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return 0;
}