Final (I think) version of xargs. Throw away all that tedious string
scrubbing, and quit using system. Instead, use fork() and exec(), which
yields and smaller, simpler, and cleaner design.
-Erik
diff --git a/findutils/xargs.c b/findutils/xargs.c
index 21bfb6b..b8ac31a 100644
--- a/findutils/xargs.c
+++ b/findutils/xargs.c
@@ -28,68 +28,19 @@
#include <errno.h>
#include <getopt.h>
#include <ctype.h>
-
-/* get_sh_safe_line_from_file() - This function reads an entire line from a text file
- * up to a newline. It returns a malloc'ed char * which must be stored and
- * free'ed by the caller. */
-extern char *get_sh_safe_line_from_file(FILE *file)
-{
- static const int GROWBY = 80; /* how large we will grow strings by */
-
- char ch, last_ch = 0;
- char tmp[]=" ";
- int idx = 0;
- char *linebuf = NULL;
- int linebufsz = 0;
-
- while (1) {
- ch = fgetc(file);
- if (ch == EOF)
- break;
-
- /* grow the line buffer as necessary */
- while (idx > linebufsz-4)
- linebuf = xrealloc(linebuf, linebufsz += GROWBY);
-
- /* Remove any extra spaces */
- if (last_ch == ' ' && ch == ' ')
- continue;
-
- /* Replace any tabs with spaces */
- if (ch == '\t')
- ch=' ';
-
- /* Escape any characters that are treated specially by /bin/sh */
- *tmp=ch;
- if (strpbrk(tmp, "\\~`!$^&*()=|{}[];\"'<>?#") != NULL && last_ch!='\\') {
- linebuf[idx++] = '\\';
- }
-
- linebuf[idx++] = ch;
- last_ch=ch;
-
- if (ch == '\n')
- break;
- }
- if (idx == 0 && last_ch!=0)
- linebuf[idx++]=' ';
-
- if (idx == 0)
- return NULL;
-
- linebuf[idx] = 0;
- return linebuf;
-}
-
+#include <sys/types.h>
+#include <sys/wait.h>
int xargs_main(int argc, char **argv)
{
char *in_from_stdin = NULL;
- char *args_from_cmdline = NULL;
+ char *args = NULL;
char *cmd_to_be_executed = NULL;
char traceflag = 0;
- int len_args_from_cmdline, len_cmd_to_be_executed, len, opt;
+ int len_args=10, len_cmd_to_be_executed, opt;
+ pid_t pid;
+ int wpid, status;
/* Note that we do not use getopt here, since
* we only want to interpret initial options,
@@ -102,50 +53,45 @@
break;
default:
fatalError(xargs_usage);
- }
+ }
}
}
- /* Store the command and arguments to be executed (from the command line) */
+ /* Store the command to be executed (taken from the command line) */
if (argc == 0) {
- len_args_from_cmdline = 6;
- args_from_cmdline = xmalloc(len_args_from_cmdline);
- strcat(args_from_cmdline, "echo ");
+ len_cmd_to_be_executed=6;
+ cmd_to_be_executed = xmalloc(len_cmd_to_be_executed);
+ strcat(cmd_to_be_executed, "echo");
} else {
opt=strlen(*argv);
- len_args_from_cmdline = (opt > 10)? opt : 10;
- args_from_cmdline = xcalloc(len_args_from_cmdline, sizeof(char));
- while (argc-- > 0) {
- if (strlen(*argv) + strlen(args_from_cmdline) >
- len_args_from_cmdline) {
- len_args_from_cmdline += strlen(*argv);
- args_from_cmdline =
- xrealloc(args_from_cmdline,
- len_args_from_cmdline+1);
- }
- strcat(args_from_cmdline, *argv);
- strcat(args_from_cmdline, " ");
- ++argv;
- }
+ len_cmd_to_be_executed = (opt > 10)? opt : 10;
+ cmd_to_be_executed = xcalloc(len_cmd_to_be_executed, sizeof(char));
+ strcat(cmd_to_be_executed, *argv);
}
- /* Set up some space for the command to be executed to be held in */
- len_cmd_to_be_executed=10;
- cmd_to_be_executed = xcalloc(len_cmd_to_be_executed, sizeof(char));
- strcpy(cmd_to_be_executed, args_from_cmdline);
- /* Now, read in one line at a time from stdin, and run command+args on it */
- in_from_stdin = get_sh_safe_line_from_file(stdin);
+ /* Now, read in one line at a time from stdin, and stroe this to be used later
+ * as an argument to the command we just stored */
+ in_from_stdin = get_line_from_file(stdin);
for (;in_from_stdin!=NULL;) {
char *tmp;
opt = strlen(in_from_stdin);
- len = opt + len_args_from_cmdline;
- len_cmd_to_be_executed+=len+3;
- cmd_to_be_executed=xrealloc(cmd_to_be_executed, len_cmd_to_be_executed);
+ len_args += opt + 3;
+ args=xrealloc(args, len_args);
/* Strip out the final \n */
in_from_stdin[opt-1]=' ';
-
+
+ /* Replace any tabs with spaces */
+ while( (tmp = strchr(in_from_stdin, '\t')) != NULL )
+ *tmp=' ';
+
+ /* Strip out any extra intra-word spaces */
+ while( (tmp = strstr(in_from_stdin, " ")) != NULL ) {
+ opt = strlen(in_from_stdin);
+ memmove(tmp, tmp+1, opt-(tmp-in_from_stdin));
+ }
+
/* trim trailing whitespace */
opt = strlen(in_from_stdin) - 1;
while (isspace(in_from_stdin[opt]))
@@ -157,26 +103,49 @@
while(isspace(*tmp))
tmp++;
- strcat(cmd_to_be_executed, tmp);
- strcat(cmd_to_be_executed, " ");
-
+ strcat(args, tmp);
+ strcat(args, " ");
+
free(in_from_stdin);
- in_from_stdin = get_sh_safe_line_from_file(stdin);
+ in_from_stdin = get_line_from_file(stdin);
}
- if (traceflag==1)
+ if (traceflag==1) {
fputs(cmd_to_be_executed, stderr);
+ fputs(args, stderr);
+ }
- if ((system(cmd_to_be_executed) != 0) && (errno != 0))
- fatalError("%s", strerror(errno));
+ if ((pid = fork()) == 0) {
+ char *cmd[255];
+ int i=1;
+
+ //printf("argv[0]='%s'\n", cmd_to_be_executed);
+ cmd[0] = cmd_to_be_executed;
+ while (--argc && ++argv && *argv ) {
+ //printf("argv[%d]='%s'\n", i, *argv);
+ cmd[i++]=*argv;
+ }
+ //printf("argv[%d]='%s'\n", i, args);
+ cmd[i++] = args;
+ cmd[i] = NULL;
+ execvp(cmd_to_be_executed, cmd);
+
+ /* What? Still here? Exit with an error */
+ fatalError("%s: %s\n", cmd_to_be_executed, strerror(errno));
+ }
+ /* Wait for a child process to exit */
+ wpid = wait(&status);
#ifdef BB_FEATURE_CLEAN_UP
- free(args_from_cmdline);
+ free(args);
free(cmd_to_be_executed);
#endif
- return 0;
+ if (wpid > 0)
+ return (WEXITSTATUS(status));
+ else
+ return EXIT_FAILURE;
}
/*
Local Variables:
@@ -185,4 +154,3 @@
tab-width: 4
End:
*/
-
diff --git a/xargs.c b/xargs.c
index 21bfb6b..b8ac31a 100644
--- a/xargs.c
+++ b/xargs.c
@@ -28,68 +28,19 @@
#include <errno.h>
#include <getopt.h>
#include <ctype.h>
-
-/* get_sh_safe_line_from_file() - This function reads an entire line from a text file
- * up to a newline. It returns a malloc'ed char * which must be stored and
- * free'ed by the caller. */
-extern char *get_sh_safe_line_from_file(FILE *file)
-{
- static const int GROWBY = 80; /* how large we will grow strings by */
-
- char ch, last_ch = 0;
- char tmp[]=" ";
- int idx = 0;
- char *linebuf = NULL;
- int linebufsz = 0;
-
- while (1) {
- ch = fgetc(file);
- if (ch == EOF)
- break;
-
- /* grow the line buffer as necessary */
- while (idx > linebufsz-4)
- linebuf = xrealloc(linebuf, linebufsz += GROWBY);
-
- /* Remove any extra spaces */
- if (last_ch == ' ' && ch == ' ')
- continue;
-
- /* Replace any tabs with spaces */
- if (ch == '\t')
- ch=' ';
-
- /* Escape any characters that are treated specially by /bin/sh */
- *tmp=ch;
- if (strpbrk(tmp, "\\~`!$^&*()=|{}[];\"'<>?#") != NULL && last_ch!='\\') {
- linebuf[idx++] = '\\';
- }
-
- linebuf[idx++] = ch;
- last_ch=ch;
-
- if (ch == '\n')
- break;
- }
- if (idx == 0 && last_ch!=0)
- linebuf[idx++]=' ';
-
- if (idx == 0)
- return NULL;
-
- linebuf[idx] = 0;
- return linebuf;
-}
-
+#include <sys/types.h>
+#include <sys/wait.h>
int xargs_main(int argc, char **argv)
{
char *in_from_stdin = NULL;
- char *args_from_cmdline = NULL;
+ char *args = NULL;
char *cmd_to_be_executed = NULL;
char traceflag = 0;
- int len_args_from_cmdline, len_cmd_to_be_executed, len, opt;
+ int len_args=10, len_cmd_to_be_executed, opt;
+ pid_t pid;
+ int wpid, status;
/* Note that we do not use getopt here, since
* we only want to interpret initial options,
@@ -102,50 +53,45 @@
break;
default:
fatalError(xargs_usage);
- }
+ }
}
}
- /* Store the command and arguments to be executed (from the command line) */
+ /* Store the command to be executed (taken from the command line) */
if (argc == 0) {
- len_args_from_cmdline = 6;
- args_from_cmdline = xmalloc(len_args_from_cmdline);
- strcat(args_from_cmdline, "echo ");
+ len_cmd_to_be_executed=6;
+ cmd_to_be_executed = xmalloc(len_cmd_to_be_executed);
+ strcat(cmd_to_be_executed, "echo");
} else {
opt=strlen(*argv);
- len_args_from_cmdline = (opt > 10)? opt : 10;
- args_from_cmdline = xcalloc(len_args_from_cmdline, sizeof(char));
- while (argc-- > 0) {
- if (strlen(*argv) + strlen(args_from_cmdline) >
- len_args_from_cmdline) {
- len_args_from_cmdline += strlen(*argv);
- args_from_cmdline =
- xrealloc(args_from_cmdline,
- len_args_from_cmdline+1);
- }
- strcat(args_from_cmdline, *argv);
- strcat(args_from_cmdline, " ");
- ++argv;
- }
+ len_cmd_to_be_executed = (opt > 10)? opt : 10;
+ cmd_to_be_executed = xcalloc(len_cmd_to_be_executed, sizeof(char));
+ strcat(cmd_to_be_executed, *argv);
}
- /* Set up some space for the command to be executed to be held in */
- len_cmd_to_be_executed=10;
- cmd_to_be_executed = xcalloc(len_cmd_to_be_executed, sizeof(char));
- strcpy(cmd_to_be_executed, args_from_cmdline);
- /* Now, read in one line at a time from stdin, and run command+args on it */
- in_from_stdin = get_sh_safe_line_from_file(stdin);
+ /* Now, read in one line at a time from stdin, and stroe this to be used later
+ * as an argument to the command we just stored */
+ in_from_stdin = get_line_from_file(stdin);
for (;in_from_stdin!=NULL;) {
char *tmp;
opt = strlen(in_from_stdin);
- len = opt + len_args_from_cmdline;
- len_cmd_to_be_executed+=len+3;
- cmd_to_be_executed=xrealloc(cmd_to_be_executed, len_cmd_to_be_executed);
+ len_args += opt + 3;
+ args=xrealloc(args, len_args);
/* Strip out the final \n */
in_from_stdin[opt-1]=' ';
-
+
+ /* Replace any tabs with spaces */
+ while( (tmp = strchr(in_from_stdin, '\t')) != NULL )
+ *tmp=' ';
+
+ /* Strip out any extra intra-word spaces */
+ while( (tmp = strstr(in_from_stdin, " ")) != NULL ) {
+ opt = strlen(in_from_stdin);
+ memmove(tmp, tmp+1, opt-(tmp-in_from_stdin));
+ }
+
/* trim trailing whitespace */
opt = strlen(in_from_stdin) - 1;
while (isspace(in_from_stdin[opt]))
@@ -157,26 +103,49 @@
while(isspace(*tmp))
tmp++;
- strcat(cmd_to_be_executed, tmp);
- strcat(cmd_to_be_executed, " ");
-
+ strcat(args, tmp);
+ strcat(args, " ");
+
free(in_from_stdin);
- in_from_stdin = get_sh_safe_line_from_file(stdin);
+ in_from_stdin = get_line_from_file(stdin);
}
- if (traceflag==1)
+ if (traceflag==1) {
fputs(cmd_to_be_executed, stderr);
+ fputs(args, stderr);
+ }
- if ((system(cmd_to_be_executed) != 0) && (errno != 0))
- fatalError("%s", strerror(errno));
+ if ((pid = fork()) == 0) {
+ char *cmd[255];
+ int i=1;
+
+ //printf("argv[0]='%s'\n", cmd_to_be_executed);
+ cmd[0] = cmd_to_be_executed;
+ while (--argc && ++argv && *argv ) {
+ //printf("argv[%d]='%s'\n", i, *argv);
+ cmd[i++]=*argv;
+ }
+ //printf("argv[%d]='%s'\n", i, args);
+ cmd[i++] = args;
+ cmd[i] = NULL;
+ execvp(cmd_to_be_executed, cmd);
+
+ /* What? Still here? Exit with an error */
+ fatalError("%s: %s\n", cmd_to_be_executed, strerror(errno));
+ }
+ /* Wait for a child process to exit */
+ wpid = wait(&status);
#ifdef BB_FEATURE_CLEAN_UP
- free(args_from_cmdline);
+ free(args);
free(cmd_to_be_executed);
#endif
- return 0;
+ if (wpid > 0)
+ return (WEXITSTATUS(status));
+ else
+ return EXIT_FAILURE;
}
/*
Local Variables:
@@ -185,4 +154,3 @@
tab-width: 4
End:
*/
-