X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=findutils%2Fxargs.c;h=0d1bb43fc89a7e05ee06627342762f0149c1b0d2;hb=df9196d824ea9bca7590edade631362e89b5c6ce;hp=c55ac5724e795665c277da8abe9c3dc0df4fd64b;hpb=7fb68f199f037cb69363c8df5c934a27adc699f7;p=oweals%2Fbusybox.git diff --git a/findutils/xargs.c b/findutils/xargs.c index c55ac5724..0d1bb43fc 100644 --- a/findutils/xargs.c +++ b/findutils/xargs.c @@ -1,7 +1,6 @@ /* vi: set sw=4 ts=4: */ /* * Mini xargs implementation for busybox - * Options are supported: "-prtx -n max_arg -s max_chars -e[ouf_str]" * * (C) 2002,2003 by Vladimir Oleynik * @@ -10,25 +9,22 @@ * - Mike Rendell * and David MacKenzie . * - * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. + * Licensed under GPLv2 or later, see file LICENSE in this source tree. * * xargs is described in the Single Unix Specification v3 at * http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html - * */ -//kbuild:lib-$(CONFIG_XARGS) += xargs.o -//config: //config:config XARGS //config: bool "xargs" -//config: default n +//config: default y //config: help //config: xargs is used to execute a specified command for //config: every item from standard input. //config: //config:config FEATURE_XARGS_SUPPORT_CONFIRMATION //config: bool "Enable -p: prompt and confirmation" -//config: default n +//config: default y //config: depends on XARGS //config: help //config: Support -p: prompt the user whether to run each command @@ -36,14 +32,14 @@ //config: //config:config FEATURE_XARGS_SUPPORT_QUOTES //config: bool "Enable single and double quotes and backslash" -//config: default n +//config: default y //config: depends on XARGS //config: help //config: Support quoting in the input. //config: //config:config FEATURE_XARGS_SUPPORT_TERMOPT //config: bool "Enable -x: exit if -s or -n is exceeded" -//config: default n +//config: default y //config: depends on XARGS //config: help //config: Support -x: exit if the command size (see the -s or -n option) @@ -51,26 +47,24 @@ //config: //config:config FEATURE_XARGS_SUPPORT_ZERO_TERM //config: bool "Enable -0: NUL-terminated input" -//config: default n +//config: default y //config: depends on XARGS //config: help //config: Support -0: input items are terminated by a NUL character //config: instead of whitespace, and the quotes and backslash //config: are not special. +//applet:IF_XARGS(APPLET_NOEXEC(xargs, xargs, BB_DIR_USR_BIN, BB_SUID_DROP, xargs)) + +//kbuild:lib-$(CONFIG_XARGS) += xargs.o + #include "libbb.h" /* This is a NOEXEC applet. Be very careful! */ -/* COMPAT: SYSV version defaults size (and has a max value of) to 470. - We try to make it as large as possible. */ -#if !defined(ARG_MAX) && defined(_SC_ARG_MAX) -# define ARG_MAX sysconf(_SC_ARG_MAX) -#endif -#if !defined(ARG_MAX) -# define ARG_MAX 470 -#endif +//#define dbg_msg(...) bb_error_msg(__VA_ARGS__) +#define dbg_msg(...) ((void)0) #ifdef TEST @@ -88,26 +82,38 @@ # endif #endif + +struct globals { + char **args; + const char *eof_str; + int idx; +} FIX_ALIASING; +#define G (*(struct globals*)&bb_common_bufsiz1) +#define INIT_G() do { \ + G.eof_str = NULL; /* need to clear by hand because we are NOEXEC applet */ \ +} while (0) + + /* - This function has special algorithm. - Don't use fork and include to main! -*/ -static int xargs_exec(char **args) + * This function has special algorithm. + * Don't use fork and include to main! + */ +static int xargs_exec(void) { int status; - status = spawn_and_wait(args); + status = spawn_and_wait(G.args); if (status < 0) { - bb_simple_perror_msg(args[0]); + bb_simple_perror_msg(G.args[0]); return errno == ENOENT ? 127 : 126; } if (status == 255) { - bb_error_msg("%s: exited with status 255; aborting", args[0]); + bb_error_msg("%s: exited with status 255; aborting", G.args[0]); return 124; } if (status >= 0x180) { bb_error_msg("%s: terminated by signal %d", - args[0], status - 0x180); + G.args[0], status - 0x180); return 125; } if (status) @@ -115,75 +121,75 @@ static int xargs_exec(char **args) return 0; } +/* In POSIX/C locale isspace is only these chars: "\t\n\v\f\r" and space. + * "\t\n\v\f\r" happen to have ASCII codes 9,10,11,12,13. + */ +#define ISSPACE(a) ({ unsigned char xargs__isspace = (a) - 9; xargs__isspace == (' ' - 9) || xargs__isspace <= (13 - 9); }) -typedef struct xlist_t { - struct xlist_t *link; - size_t length; - char xstr[1]; -} xlist_t; - -static smallint eof_stdin_detected; +static void store_param(char *s) +{ + /* Grow by 256 elements at once */ + if (!(G.idx & 0xff)) { /* G.idx == N*256 */ + /* Enlarge, make G.args[(N+1)*256 - 1] last valid idx */ + G.args = xrealloc(G.args, sizeof(G.args[0]) * (G.idx + 0x100)); + } + G.args[G.idx++] = s; +} -#define ISBLANK(c) ((c) == ' ' || (c) == '\t') -#define ISSPACE(c) (ISBLANK(c) || (c) == '\n' || (c) == '\r' \ - || (c) == '\f' || (c) == '\v') +/* process[0]_stdin: + * Read characters into buf[n_max_chars+1], and when parameter delimiter + * is seen, store the address of a new parameter to args[]. + * If reading discovers that last chars do not form the complete + * parameter, the pointer to the first such "tail character" is returned. + * (buf has extra byte at the end to accomodate terminating NUL + * of "tail characters" string). + * Otherwise, the returned pointer points to NUL byte. + * On entry, buf[] may contain some "seed chars" which are to become + * the beginning of the first parameter. + */ #if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES -static xlist_t *process_stdin(xlist_t *list_arg, - const char *eof_str, size_t mc, char *buf) +static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf) { #define NORM 0 #define QUOTE 1 #define BACKSLASH 2 #define SPACE 4 - - char *s = NULL; /* start word */ - char *p = NULL; /* pointer to end word */ - char q = '\0'; /* quote char */ + char q = '\0'; /* quote char */ char state = NORM; - char eof_str_detected = 0; - size_t line_l = 0; /* size loaded args line */ - int c; /* current char */ - xlist_t *cur; - xlist_t *prev; + char *s = buf; /* start of the word */ + char *p = s + strlen(buf); /* end of the word */ - prev = cur = list_arg; - while (1) { - if (!cur) break; - prev = cur; - line_l += cur->length; - cur = cur->link; - } + buf += n_max_chars; /* past buffer's end */ + + /* "goto ret" is used instead of "break" to make control flow + * more obvious: */ - while (!eof_stdin_detected) { - c = getchar(); + while (1) { + int c = getchar(); if (c == EOF) { - eof_stdin_detected = 1; - if (s) - goto unexpected_eof; - break; + if (p != s) + goto close_word; + goto ret; } - if (eof_str_detected) - continue; if (state == BACKSLASH) { state = NORM; goto set; - } else if (state == QUOTE) { + } + if (state == QUOTE) { if (c != q) goto set; q = '\0'; state = NORM; } else { /* if (state == NORM) */ if (ISSPACE(c)) { - if (s) { - unexpected_eof: + if (p != s) { + close_word: state = SPACE; c = '\0'; goto set; } } else { - if (s == NULL) - s = p = buf; if (c == '\\') { state = BACKSLASH; } else if (c == '\'' || c == '"') { @@ -191,8 +197,6 @@ static xlist_t *process_stdin(xlist_t *list_arg, state = QUOTE; } else { set: - if ((size_t)(p - buf) >= mc) - bb_error_msg_and_die("argument line too long"); *p++ = c; } } @@ -202,105 +206,122 @@ static xlist_t *process_stdin(xlist_t *list_arg, bb_error_msg_and_die("unmatched %s quote", q == '\'' ? "single" : "double"); } - /* word loaded */ - if (eof_str) { - eof_str_detected = (strcmp(s, eof_str) == 0); - } - if (!eof_str_detected) { - size_t length = (p - buf); - /* Dont xzalloc - it can be quite big */ - cur = xmalloc(offsetof(xlist_t, xstr) + length); - cur->link = NULL; - cur->length = length; - memcpy(cur->xstr, s, length); - if (prev == NULL) { - list_arg = cur; - } else { - prev->link = cur; - } - prev = cur; - line_l += length; - if (line_l > mc) { - /* stop memory usage :-) */ - break; + /* A full word is loaded */ + if (G.eof_str) { + if (strcmp(s, G.eof_str) == 0) { + while (getchar() != EOF) + continue; + p = s; + goto ret; } } - s = NULL; + store_param(s); + dbg_msg("args[]:'%s'", s); + s = p; + n_max_arg--; + if (n_max_arg == 0) { + goto ret; + } state = NORM; } + if (p == buf) { + goto ret; + } } - return list_arg; + ret: + *p = '\0'; + /* store_param(NULL) - caller will do it */ + dbg_msg("return:'%s'", s); + return s; } #else /* The variant does not support single quotes, double quotes or backslash */ -static xlist_t *process_stdin(xlist_t *list_arg, - const char *eof_str, size_t mc, char *buf) +static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf) { + char *s = buf; /* start of the word */ + char *p = s + strlen(buf); /* end of the word */ - int c; /* current char */ - char eof_str_detected = 0; - char *s = NULL; /* start word */ - char *p = NULL; /* pointer to end word */ - size_t line_l = 0; /* size loaded args line */ - xlist_t *cur; - xlist_t *prev; + buf += n_max_chars; /* past buffer's end */ - prev = cur = list_arg; while (1) { - if (!cur) break; - prev = cur; - line_l += cur->length; - cur = cur->link; - } - - while (!eof_stdin_detected) { - c = getchar(); + int c = getchar(); if (c == EOF) { - eof_stdin_detected = 1; + if (p == s) + goto ret; } - if (eof_str_detected) - continue; if (c == EOF || ISSPACE(c)) { - if (s == NULL) + if (p == s) continue; c = EOF; } - if (s == NULL) - s = p = buf; - if ((size_t)(p - buf) >= mc) - bb_error_msg_and_die("argument line too long"); *p++ = (c == EOF ? '\0' : c); if (c == EOF) { /* word's delimiter or EOF detected */ - /* word loaded */ - if (eof_str) { - eof_str_detected = (strcmp(s, eof_str) == 0); - } - if (!eof_str_detected) { - size_t length = (p - buf); - /* Dont xzalloc - it can be quite big */ - cur = xmalloc(offsetof(xlist_t, xstr) + length); - cur->link = NULL; - cur->length = length; - memcpy(cur->xstr, s, length); - if (prev == NULL) { - list_arg = cur; - } else { - prev->link = cur; + /* A full word is loaded */ + if (G.eof_str) { + if (strcmp(s, G.eof_str) == 0) { + while (getchar() != EOF) + continue; + p = s; + goto ret; } - prev = cur; - line_l += length; - if (line_l > mc) { - /* stop memory usage :-) */ - break; - } - s = NULL; + } + store_param(s); + dbg_msg("args[]:'%s'", s); + s = p; + n_max_arg--; + if (n_max_arg == 0) { + goto ret; } } + if (p == buf) { + goto ret; + } } - return list_arg; + ret: + *p = '\0'; + /* store_param(NULL) - caller will do it */ + dbg_msg("return:'%s'", s); + return s; } #endif /* FEATURE_XARGS_SUPPORT_QUOTES */ +#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM +static char* FAST_FUNC process0_stdin(int n_max_chars, int n_max_arg, char *buf) +{ + char *s = buf; /* start of the word */ + char *p = s + strlen(buf); /* end of the word */ + + buf += n_max_chars; /* past buffer's end */ + + while (1) { + int c = getchar(); + if (c == EOF) { + if (p == s) + goto ret; + c = '\0'; + } + *p++ = c; + if (c == '\0') { /* word's delimiter or EOF detected */ + /* A full word is loaded */ + store_param(s); + dbg_msg("args[]:'%s'", s); + s = p; + n_max_arg--; + if (n_max_arg == 0) { + goto ret; + } + } + if (p == buf) { + goto ret; + } + } + ret: + *p = '\0'; + /* store_param(NULL) - caller will do it */ + dbg_msg("return:'%s'", s); + return s; +} +#endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */ #if ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION /* Prompt the user for a response, and @@ -322,65 +343,29 @@ static int xargs_ask_confirmation(void) } #else # define xargs_ask_confirmation() 1 -#endif /* FEATURE_XARGS_SUPPORT_CONFIRMATION */ - -#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM -static xlist_t *process0_stdin(xlist_t *list_arg, - const char *eof_str UNUSED_PARAM, size_t mc, char *buf) -{ - int c; /* current char */ - char *s = NULL; /* start word */ - char *p = NULL; /* pointer to end word */ - size_t line_l = 0; /* size loaded args line */ - xlist_t *cur; - xlist_t *prev; - - prev = cur = list_arg; - while (1) { - if (!cur) break; - prev = cur; - line_l += cur->length; - cur = cur->link; - } +#endif - while (!eof_stdin_detected) { - c = getchar(); - if (c == EOF) { - eof_stdin_detected = 1; - if (s == NULL) - break; - c = '\0'; - } - if (s == NULL) - s = p = buf; - if ((size_t)(p - buf) >= mc) - bb_error_msg_and_die("argument line too long"); - *p++ = c; - if (c == '\0') { /* word's delimiter or EOF detected */ - /* word loaded */ - size_t length = (p - buf); - /* Dont xzalloc - it can be quite big */ - cur = xmalloc(offsetof(xlist_t, xstr) + length); - cur->link = NULL; - cur->length = length; - memcpy(cur->xstr, s, length); - if (prev == NULL) { - list_arg = cur; - } else { - prev->link = cur; - } - prev = cur; - line_l += length; - if (line_l > mc) { - /* stop memory usage :-) */ - break; - } - s = NULL; - } - } - return list_arg; -} -#endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */ +//usage:#define xargs_trivial_usage +//usage: "[OPTIONS] [PROG ARGS]" +//usage:#define xargs_full_usage "\n\n" +//usage: "Run PROG on every item given by stdin\n" +//usage: IF_FEATURE_XARGS_SUPPORT_CONFIRMATION( +//usage: "\n -p Ask user whether to run each command" +//usage: ) +//usage: "\n -r Don't run command if input is empty" +//usage: IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( +//usage: "\n -0 Input is separated by NUL characters" +//usage: ) +//usage: "\n -t Print the command on stderr before execution" +//usage: "\n -e[STR] STR stops input processing" +//usage: "\n -n N Pass no more than N args to PROG" +//usage: "\n -s N Pass command line of no more than N bytes" +//usage: IF_FEATURE_XARGS_SUPPORT_TERMOPT( +//usage: "\n -x Exit if size is exceeded" +//usage: ) +//usage:#define xargs_example_usage +//usage: "$ ls | xargs gzip\n" +//usage: "$ find . -name '*.c' -print | xargs rm\n" /* Correct regardless of combination of CONFIG_xxx */ enum { @@ -412,146 +397,152 @@ enum { int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int xargs_main(int argc, char **argv) { - char **args; - int i, n; - xlist_t *list = NULL; - xlist_t *cur; + int i; int child_error = 0; - char *max_args, *max_chars; - int n_max_arg; - const char *eof_str = NULL; + char *max_args; + char *max_chars; + char *buf; unsigned opt; - size_t n_max_chars; + int n_max_chars; + int n_max_arg; #if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM - xlist_t* (*read_args)(xlist_t*, const char*, size_t, char*) = process_stdin; + char* FAST_FUNC (*read_args)(int, int, char*) = process_stdin; #else #define read_args process_stdin #endif - opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &eof_str, &eof_str); + INIT_G(); + +#if ENABLE_DESKTOP && ENABLE_LONG_OPTS + /* For example, Fedora's build system uses --no-run-if-empty */ + applet_long_options = + "no-run-if-empty\0" No_argument "r" + ; +#endif + opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &G.eof_str, &G.eof_str); /* -E ""? You may wonder why not just omit -E? * This is used for portability: * old xargs was using "_" as default for -E / -e */ - if ((opt & OPT_EOF_STRING1) && eof_str[0] == '\0') - eof_str = NULL; + if ((opt & OPT_EOF_STRING1) && G.eof_str[0] == '\0') + G.eof_str = NULL; if (opt & OPT_ZEROTERM) IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin); argv += optind; argc -= optind; - if (!argc) { + if (!argv[0]) { /* default behavior is to echo all the filenames */ - *argv = (char*)"echo"; + *--argv = (char*)"echo"; argc++; } - n_max_chars = ARG_MAX; /* might be calling sysconf(_SC_ARG_MAX) */ - if (n_max_chars < 4*1024); /* paranoia */ - n_max_chars = LONG_MAX; - /* The Open Group Base Specifications Issue 6: + /* -s NUM default. fileutils-4.4.2 uses 128k, but I heasitate + * to use such a big value - first need to change code to use + * growable buffer instead of fixed one. + */ + n_max_chars = 32 * 1024; + /* Make smaller if system does not allow our default value. + * The Open Group Base Specifications Issue 6: * "The xargs utility shall limit the command line length such that * when the command line is invoked, the combined argument * and environment lists (see the exec family of functions * in the System Interfaces volume of IEEE Std 1003.1-2001) * shall not exceed {ARG_MAX}-2048 bytes". */ - n_max_chars -= 2048; - /* Sanity check for systems with huge ARG_MAX defines (e.g., Suns which - * have it at 1 meg). Things will work fine with a large ARG_MAX but it - * will probably hurt the system more than it needs to; an array of this - * size is allocated. - */ - if (n_max_chars > 20 * 1024) - n_max_chars = 20 * 1024; - + { + long arg_max = 0; +#if defined _SC_ARG_MAX + arg_max = sysconf(_SC_ARG_MAX) - 2048; +#elif defined ARG_MAX + arg_max = ARG_MAX - 2048; +#endif + if (arg_max > 0 && n_max_chars > arg_max) + n_max_chars = arg_max; + } if (opt & OPT_UPTO_SIZE) { + n_max_chars = xatou_range(max_chars, 1, INT_MAX); + } + /* Account for prepended fixed arguments */ + { size_t n_chars = 0; - n_max_chars = xatoul_range(max_chars, 1, n_max_chars); - for (i = 0; i < argc; i++) { - n_chars += strlen(*argv) + 1; - } - if (n_max_chars <= n_chars) { - bb_error_msg_and_die("can't fit single argument within argument list size limit"); + for (i = 0; argv[i]; i++) { + n_chars += strlen(argv[i]) + 1; } n_max_chars -= n_chars; } - max_chars = xmalloc(n_max_chars); + /* Sanity check */ + if (n_max_chars <= 0) { + bb_error_msg_and_die("can't fit single argument within argument list size limit"); + } + + buf = xzalloc(n_max_chars + 1); + n_max_arg = n_max_chars; if (opt & OPT_UPTO_NUMBER) { - n_max_arg = xatoul_range(max_args, 1, INT_MAX); - } else { - n_max_arg = n_max_chars; + n_max_arg = xatou_range(max_args, 1, INT_MAX); + /* Not necessary, we use growable args[]: */ + /* if (n_max_arg > n_max_chars) n_max_arg = n_max_chars */ } - while ((list = read_args(list, eof_str, n_max_chars, max_chars)) != NULL || - !(opt & OPT_NO_EMPTY)) - { - size_t n_chars = 0; - opt |= OPT_NO_EMPTY; - n = 0; -#if ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT - for (cur = list; cur;) { - n_chars += cur->length; - n++; - cur = cur->link; - if (n_chars > n_max_chars || (n == n_max_arg && cur)) { - if (opt & OPT_TERMINATE) - bb_error_msg_and_die("argument list too long"); - break; - } - } -#else - for (cur = list; cur; cur = cur->link) { - n_chars += cur->length; - n++; - if (n_chars > n_max_chars || n == n_max_arg) { + /* Allocate pointers for execvp */ + /* We can statically allocate (argc + n_max_arg + 1) elements + * and do not bother with resizing args[], but on 64-bit machines + * this results in args[] vector which is ~8 times bigger + * than n_max_chars! That is, with n_max_chars == 20k, + * args[] will take 160k (!), which will most likely be + * almost entirely unused. + */ + /* See store_param() for matching 256-step growth logic */ + G.args = xmalloc(sizeof(G.args[0]) * ((argc + 0xff) & ~0xff)); + + /* Store the command to be executed, part 1 */ + for (i = 0; argv[i]; i++) + G.args[i] = argv[i]; + + while (1) { + char *rem; + + G.idx = argc; + rem = read_args(n_max_chars, n_max_arg, buf); + store_param(NULL); + + if (!G.args[argc]) { + if (*rem != '\0') + bb_error_msg_and_die("argument line too long"); + if (opt & OPT_NO_EMPTY) break; - } - } -#endif /* FEATURE_XARGS_SUPPORT_TERMOPT */ - - /* allocate pointers for execvp: - argc*arg, n*arg from stdin, NULL */ - args = xzalloc((n + argc + 1) * sizeof(char *)); - - /* store the command to be executed - (taken from the command line) */ - for (i = 0; i < argc; i++) - args[i] = argv[i]; - /* (taken from stdin) */ - for (cur = list; n; cur = cur->link) { - args[i++] = cur->xstr; - n--; } + opt |= OPT_NO_EMPTY; if (opt & (OPT_INTERACTIVE | OPT_VERBOSE)) { + const char *fmt = " %s" + 1; + char **args = G.args; for (i = 0; args[i]; i++) { - if (i) - fputc(' ', stderr); - fputs(args[i], stderr); + fprintf(stderr, fmt, args[i]); + fmt = " %s"; } if (!(opt & OPT_INTERACTIVE)) - fputc('\n', stderr); + bb_putchar_stderr('\n'); } + if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) { - child_error = xargs_exec(args); + child_error = xargs_exec(); } - /* clean up */ - for (i = argc; args[i]; i++) { - cur = list; - list = list->link; - free(cur); - } - free(args); if (child_error > 0 && child_error != 123) { break; } + + overlapping_strcpy(buf, rem); } /* while */ - if (ENABLE_FEATURE_CLEAN_UP) - free(max_chars); + + if (ENABLE_FEATURE_CLEAN_UP) { + free(G.args); + free(buf); + } + return child_error; }