diff options
Diffstat (limited to 'libbb')
-rw-r--r-- | libbb/read.c | 53 |
1 files changed, 42 insertions, 11 deletions
diff --git a/libbb/read.c b/libbb/read.c index c05b26b..05bf754 100644 --- a/libbb/read.c +++ b/libbb/read.c @@ -38,10 +38,8 @@ ssize_t full_read(int fd, void *buf, size_t len) if (cc < 0) return cc; /* read() returns -1 on failure. */ - if (cc == 0) break; - buf = ((char *)buf) + cc; total += cc; len -= cc; @@ -64,9 +62,7 @@ void xread(int fd, void *buf, size_t count) unsigned char xread_char(int fd) { char tmp; - xread(fd, &tmp, 1); - return tmp; } @@ -95,6 +91,37 @@ char *reads(int fd, char *buffer, size_t size) return buffer; } +// Read one line a-la fgets. Reads byte-by-byte. +// Useful when it is important to not read ahead. +char *xmalloc_reads(int fd, char *buf) +{ + char *p; + int sz = buf ? strlen(buf) : 0; + + goto jump_in; + while (1) { + if (p - buf == sz) { + jump_in: + buf = xrealloc(buf, sz + 128); + p = buf + sz; + sz += 128; + } + if (safe_read(fd, p, 1) != 1) { /* EOF/error */ + if (p == buf) { + /* we read nothing [and buf was NULL initially] */ + free(buf); + return NULL; + } + break; + } + if (*p == '\n') + break; + p++; + } + *p++ = '\0'; + return xrealloc(buf, p - buf); +} + ssize_t read_close(int fd, void *buf, size_t size) { int e; @@ -113,25 +140,29 @@ ssize_t open_read_close(const char *filename, void *buf, size_t size) return read_close(fd, buf, size); } +// Read (potentially big) files in one go. File size is estimated by +// lseek to end. void *xmalloc_open_read_close(const char *filename, size_t *sizep) { char *buf; size_t size = sizep ? *sizep : INT_MAX; - int fd = xopen(filename, O_RDONLY); + int fd; + off_t len; + + fd = xopen(filename, O_RDONLY); /* /proc/N/stat files report len 0 here */ /* In order to make such files readable, we add small const */ - off_t len = xlseek(fd, 0, SEEK_END) + 256; + len = xlseek(fd, 0, SEEK_END) | 0x3ff; /* + up to 1k */ xlseek(fd, 0, SEEK_SET); - - if (len > size) - bb_error_msg_and_die("file '%s' is too big", filename); - size = len; + if (len < size) + size = len; buf = xmalloc(size + 1); size = read_close(fd, buf, size); if ((ssize_t)size < 0) bb_perror_msg_and_die("'%s'", filename); xrealloc(buf, size + 1); buf[size] = '\0'; - if (sizep) *sizep = size; + if (sizep) + *sizep = size; return buf; } |